xref: /openbmc/linux/drivers/pci/hotplug/TODO (revision 7ae9fb1b7ecbb5d85d07857943f677fd1a559b18)
1*a0d58937SLukas WunnerContributions are solicited in particular to remedy the following issues:
2*a0d58937SLukas Wunner
3*a0d58937SLukas Wunnercpcihp:
4*a0d58937SLukas Wunner
5*a0d58937SLukas Wunner* There are no implementations of the ->hardware_test, ->get_power and
6*a0d58937SLukas Wunner  ->set_power callbacks in struct cpci_hp_controller_ops.  Why were they
7*a0d58937SLukas Wunner  introduced?  Can they be removed from the struct?
8*a0d58937SLukas Wunner
9*a0d58937SLukas Wunnercpqphp:
10*a0d58937SLukas Wunner
11*a0d58937SLukas Wunner* The driver spawns a kthread cpqhp_event_thread() which is woken by the
12*a0d58937SLukas Wunner  hardirq handler cpqhp_ctrl_intr().  Convert this to threaded IRQ handling.
13*a0d58937SLukas Wunner  The kthread is also woken from the timer pushbutton_helper_thread(),
14*a0d58937SLukas Wunner  convert it to call irq_wake_thread().  Use pciehp as a template.
15*a0d58937SLukas Wunner
16*a0d58937SLukas Wunner* A large portion of cpqphp_ctrl.c and cpqphp_pci.c concerns resource
17*a0d58937SLukas Wunner  management.  Doesn't this duplicate functionality in the core?
18*a0d58937SLukas Wunner
19*a0d58937SLukas Wunneribmphp:
20*a0d58937SLukas Wunner
21*a0d58937SLukas Wunner* Implementations of hotplug_slot_ops callbacks such as get_adapter_present()
22*a0d58937SLukas Wunner  in ibmphp_core.c create a copy of the struct slot on the stack, then perform
23*a0d58937SLukas Wunner  the actual operation on that copy.  Determine if this overhead is necessary,
24*a0d58937SLukas Wunner  delete it if not.  The functions also perform a NULL pointer check on the
25*a0d58937SLukas Wunner  struct hotplug_slot, this seems superfluous.
26*a0d58937SLukas Wunner
27*a0d58937SLukas Wunner* Several functions access the pci_slot member in struct hotplug_slot even
28*a0d58937SLukas Wunner  though pci_hotplug.h declares it private.  See get_max_bus_speed() for an
29*a0d58937SLukas Wunner  example.  Either the pci_slot member should no longer be declared private
30*a0d58937SLukas Wunner  or ibmphp should store a pointer to its bus in struct slot.  Probably the
31*a0d58937SLukas Wunner  former.
32*a0d58937SLukas Wunner
33*a0d58937SLukas Wunner* ibmphp_init_devno() takes a struct slot **, it could instead take a
34*a0d58937SLukas Wunner  struct slot *.
35*a0d58937SLukas Wunner
36*a0d58937SLukas Wunner* The return value of pci_hp_register() is not checked.
37*a0d58937SLukas Wunner
38*a0d58937SLukas Wunner* The various slot data structures are difficult to follow and need to be
39*a0d58937SLukas Wunner  simplified.  A lot of functions are too large and too complex, they need
40*a0d58937SLukas Wunner  to be broken up into smaller, manageable pieces.  Negative examples are
41*a0d58937SLukas Wunner  ebda_rsrc_controller() and configure_bridge().
42*a0d58937SLukas Wunner
43*a0d58937SLukas Wunner* A large portion of ibmphp_res.c and ibmphp_pci.c concerns resource
44*a0d58937SLukas Wunner  management.  Doesn't this duplicate functionality in the core?
45*a0d58937SLukas Wunner
46*a0d58937SLukas Wunnersgi_hotplug:
47*a0d58937SLukas Wunner
48*a0d58937SLukas Wunner* Several functions access the pci_slot member in struct hotplug_slot even
49*a0d58937SLukas Wunner  though pci_hotplug.h declares it private.  See sn_hp_destroy() for an
50*a0d58937SLukas Wunner  example.  Either the pci_slot member should no longer be declared private
51*a0d58937SLukas Wunner  or sgi_hotplug should store a pointer to it in struct slot.  Probably the
52*a0d58937SLukas Wunner  former.
53*a0d58937SLukas Wunner
54*a0d58937SLukas Wunnershpchp:
55*a0d58937SLukas Wunner
56*a0d58937SLukas Wunner* There is only a single implementation of struct hpc_ops.  Can the struct be
57*a0d58937SLukas Wunner  removed and its functions invoked directly?  This has already been done in
58*a0d58937SLukas Wunner  pciehp with commit 82a9e79ef132 ("PCI: pciehp: remove hpc_ops").  Clarify
59*a0d58937SLukas Wunner  if there was a specific reason not to apply the same change to shpchp.
60*a0d58937SLukas Wunner
61*a0d58937SLukas Wunner* The hardirq handler shpc_isr() queues events on a workqueue.  It can be
62*a0d58937SLukas Wunner  simplified by converting it to threaded IRQ handling.  Use pciehp as a
63*a0d58937SLukas Wunner  template.
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