Searched hist:a85a6c86 (Results 1 – 1 of 1) sorted by relevance
| /openbmc/linux/drivers/base/ |
| H A D | platform.c | a85a6c86 Mon Mar 16 16:43:38 CDT 2020 Bjorn Helgaas <bhelgaas@google.com> driver core: platform: Clarify that IRQ 0 is invalid
These interfaces return a negative error number or an IRQ:
platform_get_irq()
platform_get_irq_optional()
platform_get_irq_byname()
platform_get_irq_byname_optional()
The function comments suggest checking for error like this:
irq = platform_get_irq(...);
if (irq < 0)
return irq;
which is what most callers (~900 of 1400) do, so it's implicit that IRQ 0
is invalid. But some callers check for "irq <= 0", and it's not obvious
from the source that we never return an IRQ 0.
Make this more explicit by updating the comments to say that an IRQ number
is always non-zero and adding a WARN() if we ever do return zero. If we do
return IRQ 0, it likely indicates a bug in the arch-specific parts of
platform_get_irq().
Relevant prior discussion at [1, 2].
[1] https://lore.kernel.org/r/Pine.LNX.4.64.0701250940220.25027@woody.linux-foundation.org/
[2] https://lore.kernel.org/r/Pine.LNX.4.64.0701252029570.25027@woody.linux-foundation.org/
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
a85a6c86 Mon Mar 16 16:43:38 CDT 2020 Bjorn Helgaas <bhelgaas@google.com> driver core: platform: Clarify that IRQ 0 is invalid
These interfaces return a negative error number or an IRQ:
platform_get_irq()
platform_get_irq_optional()
platform_get_irq_byname()
platform_get_irq_byname_optional()
The function comments suggest checking for error like this:
irq = platform_get_irq(...);
if (irq < 0)
return irq;
which is what most callers (~900 of 1400) do, so it's implicit that IRQ 0
is invalid. But some callers check for "irq <= 0", and it's not obvious
from the source that we never return an IRQ 0.
Make this more explicit by updating the comments to say that an IRQ number
is always non-zero and adding a WARN() if we ever do return zero. If we do
return IRQ 0, it likely indicates a bug in the arch-specific parts of
platform_get_irq().
Relevant prior discussion at [1, 2].
[1] https://lore.kernel.org/r/Pine.LNX.4.64.0701250940220.25027@woody.linux-foundation.org/
[2] https://lore.kernel.org/r/Pine.LNX.4.64.0701252029570.25027@woody.linux-foundation.org/
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
|