Re: [PATCH 2/2] mailbox: qcom-ipcc: amend qcom_ipcc_irq_fn() to report errors

[Gabriele Paoloni]

Hi Konrad

On Tue, Mar 17, 2026 at 10:13 AM Konrad Dybcio
<konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
>
> On 3/16/26 11:26 AM, Gabriele Paoloni wrote:
> > check the virq value returned by irq_find_mapping(), also
> > check the return value of generic_handle_irq(); return IRQ_NONE
> > if either of the checks fails.
> >
> > Signed-off-by: Gabriele Paoloni <gpaoloni@xxxxxxxxxx>
> > ---
>
> It certainly seems useful to inspect a function's return value, however I
> noticed that out of 47 in-tree callers of generic_handle_irq() within
> drivers/, only one other driver (intel_lpe_audio within drm/i915) checks
> that..
>
> Similarly, many other drivers never check if irq_find_mapping() actually
> succeeded. This makes me wonder how you discovered there's an issue in
> the first place. Could you please add some details in the commit message?

Code inspection spotted the issue, and I could not find a justification for
irq_find_mapping() and generic_handle_irq() to always succeed; hence
I proposed this patch to follow good coding practices.
However if there is a justification for these functions to always succeed
in the context of use of the Qualcomm IPCC driver, I can drop this patch.

Thanks
Gab

>
> Konrad
>