usb: dwc2: Remove redundant license text

SPDX-License-Identifier have been added in commit 5fd54ace4721 ("USB: add
SPDX identifiers to all remaining files in drivers/usb/")

There is no point in kee

usb: dwc2: Remove redundant license text

SPDX-License-Identifier have been added in commit 5fd54ace4721 ("USB: add
SPDX identifiers to all remaining files in drivers/usb/")

There is no point in keeping the now redundant license text.

Remove it.

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/030a7e187d707f8734a492cda7a6b54d459c4bb3.1662788747.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

USB: dwc2: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to DesignWare USB2 DRD Core Support.
For C header files Doc

USB: dwc2: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to DesignWare USB2 DRD Core Support.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

show more ...

USB: dwc2: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to DesignWare USB2 DRD Core Support.
For C header files Doc

USB: dwc2: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to DesignWare USB2 DRD Core Support.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Link: https://lore.kernel.org/r/20200328094828.GA5016@nishad
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

USB: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
varia

USB: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20200220132017.GA29262@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

Revert "usb: dwc2: host: Setting qtd to NULL after freeing it"

This reverts commit b0d659022e5c96ee5c4bd62d22d3da2d66de306b.

The reverted commit does nothing but adding two unnecessary lines
of cod

Revert "usb: dwc2: host: Setting qtd to NULL after freeing it"

This reverts commit b0d659022e5c96ee5c4bd62d22d3da2d66de306b.

The reverted commit does nothing but adding two unnecessary lines
of code. It sets a local variable to NULL in two functions, but
that variable is not used anywhere in the rest of those functions.
This is just confusing, so let's remove it.

Cc: Vardan Mikayelyan <mvardan@synopsys.com>
Cc: John Youn <johnyoun@synopsys.com>
Cc: Douglas Anderson <dianders@chromiun.org>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: host: Fix wMaxPacketSize handling (fix webcam regression)

In commit abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return
only packet size") the API to usb_endpoint_maxp() changed. It

usb: dwc2: host: Fix wMaxPacketSize handling (fix webcam regression)

In commit abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return
only packet size") the API to usb_endpoint_maxp() changed. It used to
just return wMaxPacketSize but after that commit it returned
wMaxPacketSize with the high bits (the multiplier) masked off. If you
wanted to get the multiplier it was now up to your code to call the
new usb_endpoint_maxp_mult() which was introduced in
commit 541b6fe63023 ("usb: add helper to extract bits 12:11 of
wMaxPacketSize").

Prior to the API change most host drivers were updated, but no update
was made to dwc2. Presumably it was assumed that dwc2 was too
simplistic to use the multiplier and thus just didn't support a
certain class of USB devices. However, it turns out that dwc2 did use
the multiplier and many devices using it were working quite nicely.
That means that many USB devices have been broken since the API
change. One such device is a Logitech HD Pro Webcam C920.

Specifically, though dwc2 didn't directly call usb_endpoint_maxp(), it
did call usb_maxpacket() which in turn called usb_endpoint_maxp().

Let's update dwc2 to work properly with the new API.

Fixes: abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return only packet size")
Cc: stable@vger.kernel.org
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: host: use hrtimer for NAK retries

Modify the wait delay utilize the high resolution timer API to allow for
more precisely scheduled callbacks.

A previous commit added a 1ms retry delay a

usb: dwc2: host: use hrtimer for NAK retries

Modify the wait delay utilize the high resolution timer API to allow for
more precisely scheduled callbacks.

A previous commit added a 1ms retry delay after multiple consecutive
NAKed transactions using jiffies. On systems with a low timer interrupt
frequency, this delay may be significantly longer than specified,
resulting in misbehavior with some USB devices.

This scenario was reached on a Raspberry Pi 3B with a Macally FDD-USB
floppy drive (identified as 0424:0fdc Standard Microsystems Corp.
Floppy, based on the USB97CFDC USB FDC). With the relay delay, the drive
would be unable to mount a disk, replying with NAKs until the device was
reset.

Using ktime, the delta between starting the timer (in dwc2_hcd_qh_add)
and the callback function can be determined. With the original delay
implementation, this value was consistently approximately 12ms. (output
in us).

<idle>-0 [000] ..s. 1600.559974: dwc2_wait_timer_fn: wait_timer delta: 11976
<idle>-0 [000] ..s. 1600.571974: dwc2_wait_timer_fn: wait_timer delta: 11977
<idle>-0 [000] ..s. 1600.583974: dwc2_wait_timer_fn: wait_timer delta: 11976
<idle>-0 [000] ..s. 1600.595974: dwc2_wait_timer_fn: wait_timer delta: 11977

After converting the relay delay to using a higher resolution timer, the
delay was much closer to 1ms.

<idle>-0 [000] d.h. 1956.553017: dwc2_wait_timer_fn: wait_timer delta: 1002
<idle>-0 [000] d.h. 1956.554114: dwc2_wait_timer_fn: wait_timer delta: 1002
<idle>-0 [000] d.h. 1957.542660: dwc2_wait_timer_fn: wait_timer delta: 1004
<idle>-0 [000] d.h. 1957.543701: dwc2_wait_timer_fn: wait_timer delta: 1002

The floppy drive operates properly with delays up to approximately 5ms,
and sends NAKs for any delays that are longer.

Fixes: 38d2b5fb75c1 ("usb: dwc2: host: Don't retry NAKed transactions right away")
Cc: <stable@vger.kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Terin Stock <terin@terinstock.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: Modify dwc2_readl/writel functions prototype

Added hsotg argument to dwc2_readl/writel function prototype,
and also instead of address pass offset of register.
hsotg will contain flag fie

usb: dwc2: Modify dwc2_readl/writel functions prototype

Added hsotg argument to dwc2_readl/writel function prototype,
and also instead of address pass offset of register.
hsotg will contain flag field for endianness.

Also customized dwc2_set_bit and dwc2_clear_bit function for
dwc2_readl/writel functions.

Signed-off-by: Gevorg Sahakyan <sahakyan@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: alloc dma aligned buffer for isoc split in

The commit 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in
a more supported way") rips out a lot of code to simply the
allocation of aligned

usb: dwc2: alloc dma aligned buffer for isoc split in

The commit 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in
a more supported way") rips out a lot of code to simply the
allocation of aligned DMA. However, it also introduces a new
issue when use isoc split in transfer.

In my test case, I connect the dwc2 controller with an usb hs
Hub (GL852G-12), and plug an usb fs audio device (Plantronics
headset) into the downstream port of Hub. Then use the usb mic
to record, we can find noise when playback.

It's because that the usb Hub uses an MDATA for the first
transaction and a DATA0 for the second transaction for the isoc
split in transaction. An typical isoc split in transaction sequence
like this:

- SSPLIT IN transaction
- CSPLIT IN transaction
- MDATA packet
- CSPLIT IN transaction
- DATA0 packet

The DMA address of MDATA (urb->dma) is always DWORD-aligned, but
the DMA address of DATA0 (urb->dma + qtd->isoc_split_offset) may
not be DWORD-aligned, it depends on the qtd->isoc_split_offset (the
length of MDATA). In my test case, the length of MDATA is usually
unaligned, this cause DATA0 packet transmission error.

This patch use kmem_cache to allocate aligned DMA buf for isoc
split in transaction. Note that according to usb 2.0 spec, the
maximum data payload size is 1023 bytes for each fs isoc ep,
and the maximum allowable interrupt data payload size is 64 bytes
or less for fs interrupt ep. So we set the size of object to be
1024 bytes in the kmem cache.

Tested-by: Gevorg Sahakyan <sahakyan@synopsys.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Minas Harutyunyan hminas@synopsys.com>
Signed-off-by: William Wu <william.wu@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: Fix kernel doc's warnings.

Added descriptions for all not described parameters.
Fix all kernel doc's warnings.

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Grigor Tov

usb: dwc2: Fix kernel doc's warnings.

Added descriptions for all not described parameters.
Fix all kernel doc's warnings.

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: Delete unused functionality

Deleted dwc2_hcd_dump_frrem() function, because it used undefined
parameters from dwc2_hsotg structure. The function body was in #ifdef
statement and was never

usb: dwc2: Delete unused functionality

Deleted dwc2_hcd_dump_frrem() function, because it used undefined
parameters from dwc2_hsotg structure. The function body was in #ifdef
statement and was never compiled.

Also removed that parameters from dwc2_hsotg structure, which were
used only in dwc2_hcd_dump_frrem() function.

And also delete dwc2_sample_frrem macro, because without
dwc2_hcd_dump_frrem() function it's lose its purpose.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: host: Don't retry NAKed transactions right away

On rk3288-veyron devices on Chrome OS it was found that plugging in an
Arduino-based USB device could cause the system to lockup, especiall

usb: dwc2: host: Don't retry NAKed transactions right away

On rk3288-veyron devices on Chrome OS it was found that plugging in an
Arduino-based USB device could cause the system to lockup, especially
if the CPU Frequency was at one of the slower operating points (like
100 MHz / 200 MHz).

Upon tracing, I found that the following was happening:
* The USB device (full speed) was connected to a high speed hub and
then to the rk3288. Thus, we were dealing with split transactions,
which is all handled in software on dwc2.
* Userspace was initiating a BULK IN transfer
* When we sent the SSPLIT (to start the split transaction), we got an
ACK. Good. Then we issued the CSPLIT.
* When we sent the CSPLIT, we got back a NAK. We immediately (from
the interrupt handler) started to retry and sent another SSPLIT.
* The device kept NAKing our CSPLIT, so we kept ping-ponging between
sending a SSPLIT and a CSPLIT, each time sending from the interrupt
handler.
* The handling of the interrupts was (because of the low CPU speed and
the inefficiency of the dwc2 interrupt handler) was actually taking
_longer_ than it took the other side to send the ACK/NAK. Thus we
were _always_ in the USB interrupt routine.
* The fact that USB interrupts were always going off was preventing
other things from happening in the system. This included preventing
the system from being able to transition to a higher CPU frequency.

As I understand it, there is no requirement to retry super quickly
after a NAK, we just have to retry sometime in the future. Thus one
solution to the above is to just add a delay between getting a NAK and
retrying the transmission. If this delay is sufficiently long to get
out of the interrupt routine then the rest of the system will be able
to make forward progress. Even a 25 us delay would probably be
enough, but we'll be extra conservative and try to delay 1 ms (the
exact amount depends on HZ and the accuracy of the jiffy and how close
the current jiffy is to ticking, but could be as much as 20 ms or as
little as 1 ms).

Presumably adding a delay like this could impact the USB throughput,
so we only add the delay with repeated NAKs.

NOTE: Upon further testing of a pl2303 serial adapter, I found that
this fix may help with problems there. Specifically I found that the
pl2303 serial adapters tend to respond with a NAK when they have
nothing to say and thus we end with this same sequence.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

usb: dwc2: eliminate irq parameter from dwc2_hcd_init

The irq is available in hsotg already, so there's no need to
pass it as separate function parameter.

Acked-by: John Youn <johnyoun@synopsys.com

usb: dwc2: eliminate irq parameter from dwc2_hcd_init

The irq is available in hsotg already, so there's no need to
pass it as separate function parameter.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: Cleanup some checkpatch issues

This commmit is the result of running checkpatch --fix.

The results were verified for correctness. Some of the fixes result in
line over 80 char which we w

usb: dwc2: Cleanup some checkpatch issues

This commmit is the result of running checkpatch --fix.

The results were verified for correctness. Some of the fixes result in
line over 80 char which we will fix manually later.

The following is a summary of what was done by checkpatch:
* Remove externs on function prototypes.
* Replace symbolic permissions with octal.
* Align code to open parens.
* Replace 'unsigned' with 'unsigned int'.
* Remove unneccessary blank lines.
* Add blank lines after declarations.
* Add spaces around operators.
* Remove unnecessary spaces after casts.
* Replace 'x == NULL' with '!x'.
* Replace kzalloc() with kcalloc().
* Concatenate multi-line strings.
* Use the BIT() macro.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: Move functions from header to source

Removed extern specifier from dwc2_host_start(), dwc2_host_disconnect()
and dwc2_host_hub_info() functions. Moved those functions from header
to sourc

usb: dwc2: Move functions from header to source

Removed extern specifier from dwc2_host_start(), dwc2_host_disconnect()
and dwc2_host_hub_info() functions. Moved those functions from header
to source. Then make them static.

Signed-off-by: Razmik Karapetyan <razmik@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: Update DMA descriptor structure

Rename DMA descriptor structure from dwc2_hcd_dma_desc to dwc2_dma_desc
as it is applies to both host and gadget.

Signed-off-by: Vahram Aharonyan <vahrama

usb: dwc2: Update DMA descriptor structure

Rename DMA descriptor structure from dwc2_hcd_dma_desc to dwc2_dma_desc
as it is applies to both host and gadget.

Signed-off-by: Vahram Aharonyan <vahrama@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: host: Setting qtd to NULL after freeing it

This is safety change added while doing slub debugging.

Affected functions:
dwc2_hcd_qtd_unlink_and_free()
_dwc2_hcd_urb_enqueue()

Signed-off-

usb: dwc2: host: Setting qtd to NULL after freeing it

This is safety change added while doing slub debugging.

Affected functions:
dwc2_hcd_qtd_unlink_and_free()
_dwc2_hcd_urb_enqueue()

Signed-off-by: Vardan Mikayelyan <mvardan@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

show more ...

usb: dwc2: Move host-specific core functions into hcd.c

Move host core initialization and host channel routines into hcd.c. This
allows these functions to only be compiled in host-enabled driver
con

usb: dwc2: Move host-specific core functions into hcd.c

Move host core initialization and host channel routines into hcd.c. This
allows these functions to only be compiled in host-enabled driver
configurations (DRD or host-only).

Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

show more ...

usb: dwc2: host: Totally redo the microframe scheduler

This totally reimplements the microframe scheduler in dwc2 to attempt to
handle periodic splits properly. The old code didn't even try, so thi

usb: dwc2: host: Totally redo the microframe scheduler

This totally reimplements the microframe scheduler in dwc2 to attempt to
handle periodic splits properly. The old code didn't even try, so this
was a significant effort since periodic splits are one of the most
complicated things in USB.

I've attempted to keep the old "don't use the microframe" schduler
around for now, but not sure it's needed. It has also only been lightly
tested.

I think it's pretty certain that this scheduler isn't perfect and might
have some bugs, but it seems much better than what was there before.
With this change my stressful USB test (USB webcam + USB audio + some
keyboards) crackles less.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

show more ...

usb: dwc2: host: Manage frame nums better in scheduler

The dwc2 scheduler (contained in hcd_queue.c) was a bit confusing in the
way it initted / kept track of which frames a QH was going to be activ

usb: dwc2: host: Manage frame nums better in scheduler

The dwc2 scheduler (contained in hcd_queue.c) was a bit confusing in the
way it initted / kept track of which frames a QH was going to be active
in. Let's clean things up a little bit in preparation for a rewrite of
the microframe scheduler.

Specifically:
* Old code would pick a frame number in dwc2_qh_init() and would try to
pick it "in a slightly future (micro)frame". As far as I can tell the
reason for this was that there was a delay between dwc2_qh_init() and
when we actually wanted to dwc2_hcd_qh_add(). ...but apparently this
attempt to be slightly in the future wasn't enough because
dwc2_hcd_qh_add() then had code to reset things if the frame _wasn't_
in the future. There's no reason not to just pick the frame later.
For non-periodic QH we now pick the frame in dwc2_hcd_qh_add(). For
periodic QH we pick the frame at dwc2_schedule_periodic() time.
* The old "dwc2_qh_init() actually assigned to "hsotg->frame_number".
This doesn't seem like a great idea since that variable is supposed to
be used to keep track of which SOF the interrupt handler has seen.
Let's be clean: anyone who wants the current frame number (instead of
the one as of the last interrupt) should ask for it.
* The old code wasn't terribly consistent about trying to use the frame
that the microframe scheduler assigned to it. In
dwc2_sched_periodic_split() when it was scheduling the first frame it
always "ORed" in 0x7 (!). Since the frame goes on the wire 1 uFrame
after next_active_frame it meant that the SSPLIT would always try for
uFrame 0 and the transaction would happen on the low speed bus during
uFrame 1. This is irregardless of what the microframe scheduler
said.
* The old code assumed it would get called to schedule the next in a
periodic split very quickly. That is if next_active_frame was
0 (transfer on wire in uFrame 1) it assumed it was getting called to
schedule the next uFrame during uFrame 1 too (so it could queue
something up for uFrame 2). It should be possible to actually queue
something up for uFrame 2 while in uFrame 2 (AKA queue up ASAP). To
do this, code needs to look at the previously scheduled frame when
deciding when to next be active, not look at the current frame number.
* If there was no microframe scheduler, the old code would check for
whether we should be active using "qh->next_active_frame ==
frame_number". This seemed like a race waiting to happen. ...plus
there's no way that you wouldn't want to schedule if next_active_frame
was actually less than frame number.

Note that this change doesn't make 100% sense on its own since it's
expecting some sanity in the frame numbers assigned by the microframe
scheduler and (as per the future patch which rewries it) I think that
the current microframe scheduler is quite insane. However, it seems
like splitting this up from the microframe scheduler patch makes things
into smaller chunks and hopefully adds to clarity rather than reduces
it. The two patches could certainly be squashed. Not that in the very
least, I don't see any obvious bad behavior introduced with just this
patch.

I've attempted to keep the config parameter to disable the microframe
scheduler in tact in this change, though I'm not sure it's worth it.
Obviously the code is touched a lot so it's possible I regressed
something when the microframe scheduler is disabled, though I did some
basic testing and it seemed to work OK. I'm still not 100% sure why you
wouldn't want the microframe scheduler (presuming it works), so maybe a
future patch (or a future version of this patch?) could remove that
parameter.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

show more ...

usb: dwc2: host: Rename some fields in struct dwc2_qh

This no-op change just does some renames to simplify a future patch.

1. The "interval" field is renamed to "host_interval" to make it more
o

usb: dwc2: host: Rename some fields in struct dwc2_qh

This no-op change just does some renames to simplify a future patch.

1. The "interval" field is renamed to "host_interval" to make it more
obvious that this interval may be 8 times the interval that the
device sees (if we're doing split transactions). A future patch will
also add the "device_interval" field.
2. The "usecs" field is renamed to "host_us" again to make it more
obvious that this is the time for the transaction as seen by the
host. For split transactions the device may see a much longer
transaction time. A future patch will also add "device_us".
3. The "sched_frame" field is renamed to "next_active_frame". The name
"sched_frame" kept confusing me because it felt like something more
permament (the QH's reservation or something). The name
"next_active_frame" makes it more obvious that this field is
constantly changing.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

show more ...

usb: dwc2: host: Add a delay before releasing periodic bandwidth

We'd like to be able to use HCD_BH in order to speed up the dwc2 host
interrupt handler quite a bit. However, according to the kerne

usb: dwc2: host: Add a delay before releasing periodic bandwidth

We'd like to be able to use HCD_BH in order to speed up the dwc2 host
interrupt handler quite a bit. However, according to the kernel doc for
usb_submit_urb() (specifically the part about "Reserved Bandwidth
Transfers"), we need to keep a reservation active as long as a device
driver keeps submitting. That was easy to do when we gave back the URB
in the interrupt context: we just looked at when our queue was empty and
released the reserved bandwidth then. ...but now we need a little more
complexity.

We'll follow EHCI's lead in commit 9118f9eb4f1e ("USB: EHCI: improve
interrupt qh unlink") and add a 5ms delay. Since we don't have a whole
timer infrastructure in dwc2, we'll just add a timer per QH. The
overhead for this is very small.

Note that the dwc2 scheduler is pretty broken (see future patches to fix
it). This patch attempts to replicate all old behavior and just add the
proper delay.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

show more ...

usb: dwc2: host: Add scheduler tracing

In preparation for future changes to the scheduler let's add some
tracing that makes it easy for us to see what's happening. By default
this tracing will be o

usb: dwc2: host: Add scheduler tracing

In preparation for future changes to the scheduler let's add some
tracing that makes it easy for us to see what's happening. By default
this tracing will be off.

By changing "core.h" you can easily trace to ftrace, the console, or
nowhere.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

show more ...

usb: dwc2: host: fix split transfer schedule sequence

We're supposed to keep outstanding splits in order. Keep track of a
list of the order of splits and process channel interrupts in that
order.

usb: dwc2: host: fix split transfer schedule sequence

We're supposed to keep outstanding splits in order. Keep track of a
list of the order of splits and process channel interrupts in that
order.

Without this change and the following setup:
* Rockchip rk3288 Chromebook, using port ff540000
-> Pluggable 7-port Hub with Charging (powered)
-> Microsoft Wireless Keyboard 2000 in port 1.
-> Das Keyboard in port 2.

...I find that I get dropped keys on the Microsoft keyboard (I'm sure
there are other combinations that fail, but this documents my test).
Specifically I've been typing "hahahahahahaha" on the keyboard and often
see keys dropped or repeated.

After this change the above setup works properly. This patch is based
on a previous patch proposed by Yunzhi Li ("usb: dwc2: hcd: fix periodic
transfer schedule sequence")

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Yunzhi Li <lyz@rock-chips.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

show more ...