On Tue, Nov 17, 2020 at 08:27:28PM +0530, Vidya Sagar wrote:
> There are devices (Ex:- Marvell SATA controller) that don't support
> 64-bit MSIs and the same is advertised through their MSI capability
> register.
I *think* you're saying these devices behave correctly per spec: they
don't support 64-bit MSI, and they don't advertise support for 64-bit
MSI. Right?
> Set no_64bit_msi flag explicitly for such devices in the
> MSI setup code so that the msi_verify_entries() API would catch
> if the MSI arch code tries to use 64-bit MSI.
And you want msi_verify_entries() to catch attempts by the arch code
to assign a 64-bit MSI address?
That sounds OK, but the error message ("Device has broken 64-bit MSI")
is not appropriate if the device is actually *not* broken.
> Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
> ---
> drivers/pci/msi.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index d52d118979a6..af49da28854e 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -581,10 +581,12 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
> entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
> entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
>
> - if (control & PCI_MSI_FLAGS_64BIT)
> + if (control & PCI_MSI_FLAGS_64BIT) {
> entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
> - else
> + } else {
> entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
> + dev->no_64bit_msi = 1;
> + }
>
> /* Save the initial mask status */
> if (entry->msi_attrib.maskbit)
> --
> 2.17.1
>
