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

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

On 30/04/2022 01:07, Bjorn Helgaas wrote:
> 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.

I'm fine with either way.

> 
>> 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
>>


-- 
With best wishes
Dmitry