While IRQ test agaist the returned variable in practice is a good enough there is still a room for theoretical mistake in case the vIRQ of the device contains the same error code that acpi_register_gsi() may return. Due to this, check for error code separately from matching the vIRQs. Besides that, append documentation to tell why acpi_gsi_to_irq() can't be used and we call acpi_register_gsi() instead. Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> --- drivers/dma/acpi-dma.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c index 52768dc8ce12..5906eae26e2a 100644 --- a/drivers/dma/acpi-dma.c +++ b/drivers/dma/acpi-dma.c @@ -75,8 +75,16 @@ static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, si->mmio_base_high != upper_32_bits(mem)) return 0; - /* Match device by Linux vIRQ */ + /* + * acpi_gsi_to_irq() can't be used because some platforms do not save + * registered IRQs in the MP table. Instead we just try to register + * the GSI, which is the core part of the above mentioned function. + */ ret = acpi_register_gsi(NULL, si->gsi_interrupt, si->interrupt_mode, si->interrupt_polarity); + if (ret < 0) + return 0; + + /* Match device by Linux vIRQ */ if (ret != irq) return 0; -- 2.30.2
