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@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
