Re: [PATCH V7 02/15] PCI: Disable MSI for Tegra194 root port

[Vidya Sagar <vidyas@nvidia.com>]

On 5/21/2019 3:57 PM, Thierry Reding wrote:
> On Fri, May 17, 2019 at 06:08:33PM +0530, Vidya Sagar wrote:
>> Tegra194 rootports don't generate MSI interrupts for PME events and hence
>> MSI needs to be disabled for them to avoid root ports service drivers
>> registering their respective ISRs with MSI interrupt.
>>
>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
>> ---
>> Changes since [v6]:
>> * This is a new patch
>>
>>   drivers/pci/quirks.c | 14 ++++++++++++++
>>   1 file changed, 14 insertions(+)
>>
>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>> index 0f16acc323c6..28f9a0380df5 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -2592,6 +2592,20 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA,
>>   			PCI_DEVICE_ID_NVIDIA_NVENET_15,
>>   			nvenet_msi_disable);
>>   
>> +/*
>> + * Tegra194's PCIe root ports don't generate MSI interrupts for PME events
>> + * instead legacy interrupts are generated. Hence, to avoid service drivers
>> + * registering their respective ISRs for MSIs, need to disable MSI interrupts
>> + * for root ports.
>> + */
>> +static void disable_tegra194_rp_msi(struct pci_dev *dev)
>> +{
>> +	dev->no_msi = 1;
>> +}
>> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x1ad0, disable_tegra194_rp_msi);
>> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x1ad1, disable_tegra194_rp_msi);
>> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA, 0x1ad2, disable_tegra194_rp_msi);
>> +
> 
> Later functions in this file seem to use a more consistent naming
> pattern, according to which the name for this would become:
> 
> 	pci_quirk_nvidia_tegra194_disable_rp_msi
> 
> Might be worth considering making this consistent.
> 
> This could also be moved to the DWC driver to restrict this to where it
> is needed. In either case, this seems like a good solution, so:
> 
> Reviewed-by: Thierry Reding <treding@nvidia.com>
> 
Ok. I'll move it to DWC driver along with name change for the quirk API.