Re: [PATCH v5 1/7] PCI: qcom: Revert "PCI: qcom: Add support for handling MSIs from 8 endpoints"

[Bjorn Helgaas <helgaas@kernel.org>]

On Sat, Apr 30, 2022 at 12:42:44AM +0300, Dmitry Baryshkov wrote:
> I have replied with my Tested-by to the patch at [2], which has landed
> in the linux-next as the commit 20f1bfb8dd62 ("PCI: qcom:
> Add support for handling MSIs from 8 endpoints"). However lately I
> noticed that during the tests I still had 'pcie_pme=nomsi', so the
> device was not forced to use higher MSI vectors.
> 
> After removing this option I noticed that hight MSI vectors are not
> delivered on tested platforms. Additional research pointed to
> a patch in msm-4.14 ([1]), which describes that each group of MSI
> vectors is mapped to the separate interrupt.
> 
> Without these changes specifying num_verctors can lead to missing MSI
> interrupts and thus to devices malfunction.
> 
> Fixes: 20f1bfb8dd62 ("PCI: qcom: Add support for handling MSIs from 8 endpoints")

20f1bfb8dd62 hasn't been merged upstream yet, so I think Lorenzo can
just drop it from his pci/qcom branch so we don't need to clutter the
git history with the revert.

> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/pci/controller/dwc/pcie-qcom.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index c940e67d831c..375f27ab9403 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -1593,7 +1593,6 @@ static int qcom_pcie_probe(struct platform_device *pdev)
>  	pci->dev = dev;
>  	pci->ops = &dw_pcie_ops;
>  	pp = &pci->pp;
> -	pp->num_vectors = MAX_MSI_IRQS;
>  
>  	pcie->pci = pci;
>  
> -- 
> 2.35.1
>