Re: [PATCH v1 1/2] PCI: Disable MSI for Pericom PCIe-USB adapter

[Ben Dooks <ben.dooks@codethink.co.uk>]

On 05/11/2020 18:06, Andy Shevchenko wrote:
> Pericom PCIe-USB adapter ambiguously advertises MSI, but documentation says
> "The MSI Function is not implemented on this device." in the chapters 7.3.27,
> 7.3.29-7.3.31.
> 
> Fixes: 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI devices")
> Datasheet: https://www.diodes.com/assets/Datasheets/PI7C9X440SL.pdf
> Reported-by: alberto.vignani@fastwebnet.it
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>   drivers/pci/quirks.c | 16 ++++++++++++----
>   1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index f70692ac79c5..7df7ae50618c 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -5567,17 +5567,25 @@ static void pci_fixup_no_d0_pme(struct pci_dev *dev)
>   DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ASMEDIA, 0x2142, pci_fixup_no_d0_pme);
>   
>   /*
> - * Device [12d8:0x400e] and [12d8:0x400f]
> + * Device 12d8:0x400e [OHCI] and 12d8:0x400f [EHCI]
> + *
>    * These devices advertise PME# support in all power states but don't
>    * reliably assert it.
> + *
> + * These devices ambiguously advertise MSI, but documentation (PI7C9X440SL.pdf)
> + * says "The MSI Function is not implemented on this device." in the chapters
> + * 7.3.27, 7.3.29-7.3.31.
>    */
> -static void pci_fixup_no_pme(struct pci_dev *dev)
> +static void pci_fixup_no_msi_no_pme(struct pci_dev *dev)
>   {
> +	pci_info(dev, "The MSI Function is not implemented on this device, disabling it\n");
> +	dev->no_msi = 1;
> +
>   	pci_info(dev, "PME# is unreliable, disabling it\n");
>   	dev->pme_support = 0;
>   }


idea: one pci_info() print of:

pci_info(dev, "PME# is unreliable, MSI not implemented, disabling both\n");

> -DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_PERICOM, 0x400e, pci_fixup_no_pme);
> -DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_PERICOM, 0x400f, pci_fixup_no_pme);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_PERICOM, 0x400e, pci_fixup_no_msi_no_pme);
> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_PERICOM, 0x400f, pci_fixup_no_msi_no_pme);
>   
>   static void apex_pci_fixup_class(struct pci_dev *pdev)
>   {
> 


-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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