On Mon, Nov 29, 2021 at 10:22:41AM -0600, Pierre-Louis Bossart wrote:
On 11/25/21 1:50 AM, Tang Bin wrote:
In the function sst_platform_get_resources(), if platform_get_irq() failed, the return should not be zero, as the example in platform.c is
- int irq = platform_get_irq(pdev, 0)
- if (irq < 0)
- return irq;
So remove the redundant check to simplify the code.
Humm, it's a bit of a gray area.
the comments for platform_get_irq and platform_get_irq_optional say:
- Return: non-zero IRQ number on success, negative error number on failure.
but if you look at platform_get_irq_optional, there are two references to zero being a possible return value:
if (num == 0 && has_acpi_companion(&dev->dev)) { ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num); /* Our callers expect -ENXIO for missing IRQs. */ if (ret >= 0 || ret == -EPROBE_DEFER)
This is bogus == 0 check.
goto out;out_not_found: ret = -ENXIO; out: WARN(ret == 0, "0 is an invalid IRQ number\n"); return ret;
https://elixir.bootlin.com/linux/latest/source/drivers/base/platform.c#L234
I am not sure if there's any merit in removing the test for the zero return value. It may be on the paranoid side but it's aligned with a possible code path in the platform code.
Or it could be that the platform code is wrong, and the label used should have been
/* Our callers expect -ENXIO for missing IRQs. */ if (ret >= 0 || ret == -EPROBE_DEFER) goto out_not_found;
In case one wants to dive into new discussion on the topic:
https://lore.kernel.org/linux-serial/20220110195449.12448-2-s.shtylyov@omp.r...