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)
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;
Adding Andy Shevchenko for advice.
>
> Signed-off-by: Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx>
> ---
> sound/soc/intel/atom/sst/sst_acpi.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/sound/soc/intel/atom/sst/sst_acpi.c b/sound/soc/intel/atom/sst/sst_acpi.c
> index 3be64430c..696d547c5 100644
> --- a/sound/soc/intel/atom/sst/sst_acpi.c
> +++ b/sound/soc/intel/atom/sst/sst_acpi.c
> @@ -226,8 +226,8 @@ static int sst_platform_get_resources(struct intel_sst_drv *ctx)
> /* Find the IRQ */
> ctx->irq_num = platform_get_irq(pdev,
> ctx->pdata->res_info->acpi_ipc_irq_index);
> - if (ctx->irq_num <= 0)
> - return ctx->irq_num < 0 ? ctx->irq_num : -EIO;
> + if (ctx->irq_num < 0)
> + return ctx->irq_num;
>
> return 0;
> }
>
