Re: [PATCH V2] mfd: rtsx: release IRQ during shutdown

[Rafael J. Wysocki]

On Wed, Jan 3, 2018 at 1:32 PM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote:
> 'Commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during
> shutdown")' revealed a resource leak in rtsx_pci driver during shutdown.
>
> Issue shows up as a warning during shutdown as follows:
>
> remove_proc_entry: removing non-empty directory 'irq/17', leaking at least
> 'rtsx_pci'
> WARNING: CPU: 0 PID: 1578 at fs/proc/generic.c:572
> remove_proc_entry+0x11d/0x130
> Modules linked in <long list but none that are out-of-tree>
> ...
> Call Trace:
> unregister_irq_proc
> free_desc
> irq_free_descs
> mp_unmap_irq
> acpi_unregister_gsi_apic
> acpi_pci_irq_disable
> do_pci_disable_device
> pci_disable_device
> device_shutdown
> kernel_restart
> Sys_reboot
>
> Even though rtsx_pci driver implements a shutdown callback, it is not
> releasing the interrupt that it registered during probe. This is causing
> the ACPI layer to complain that the shared IRQ is in use while freeing
> IRQ.
>
> This code releases the IRQ to prevent resource leak and eliminate the
> warning.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=198141
> Reported-by: Chris Clayton <chris2553@xxxxxxxxxxxxxx>
> Fixes: cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown")
> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

> ---
>  drivers/mfd/rtsx_pcr.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/mfd/rtsx_pcr.c b/drivers/mfd/rtsx_pcr.c
> index 590fb9a..c3ed885 100644
> --- a/drivers/mfd/rtsx_pcr.c
> +++ b/drivers/mfd/rtsx_pcr.c
> @@ -1543,6 +1543,9 @@ static void rtsx_pci_shutdown(struct pci_dev *pcidev)
>         rtsx_pci_power_off(pcr, HOST_ENTER_S1);
>
>         pci_disable_device(pcidev);
> +       free_irq(pcr->irq, (void *)pcr);
> +       if (pcr->msi_en)
> +               pci_disable_msi(pcr->pci);
>  }
>
>  #else /* CONFIG_PM */
> --