Messages in this thread | | | Subject | Re: [PATCH] PCI/MSI: Set device flag indicating only 32-bit MSI support | From | Vidya Sagar <> | Date | Tue, 24 Nov 2020 09:27:06 +0530 |
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On 11/21/2020 3:00 AM, Bjorn Helgaas wrote: > External email: Use caution opening links or attachments > > > 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? Yes. That is what I intended to say.
> >> 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? Yes.
> > That sounds OK, but the error message ("Device has broken 64-bit MSI") > is not appropriate if the device is actually *not* broken. Ok. I didn't change the existing error message. I'll change it to cover both the scenarios i.e. either the device is broken or the device doesn't really support 64-bit MSI.
> >> Signed-off-by: Vidya Sagar <vidyas@nvidia.com> >> --- >> 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 >>
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