On 04/05/2022 17:59, Bjorn Helgaas wrote:
On Wed, May 04, 2022 at 04:12:39PM +0100, Conor Dooley wrote:
On 02/05/2022 20:22, Bjorn Helgaas wrote:
On Sat, Apr 30, 2022 at 12:33:51AM +0100, Marc Zyngier wrote:
On Fri, 29 Apr 2022 22:57:33 +0100,
Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
On Fri, Apr 29, 2022 at 09:42:52AM +0000, Conor.Dooley@xxxxxxxxxxxxx wrote:
On 28/04/2022 10:29, Lorenzo Pieralisi wrote:
On Tue, Apr 05, 2022 at 12:17:51PM +0100, daire.mcnamara@xxxxxxxxxxxxx wrote:
From: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
Clear MSI bit in ISTATUS register after reading it before
handling individual MSI bits
Clear the MSI bit in ISTATUS register after reading it, but before
reading and handling individual MSI bits from the IMSI register.
This avoids a potential race where new MSI bits may be set on the
IMSI register after it was read and be missed when the MSI bit in
the ISTATUS register is cleared.
Restoring the context here:
"ISTATUS" doesn't appear in the code as a register name.
Neither does "IMSI". Please use names that match the code.
Daire is still having the IT issues, so before I resend the patch with
a new commit message, how is the following:
Clear the MSI bit in ISTATUS_LOCAL register after reading it, but
before reading and handling individual MSI bits from the ISTATUS_MSI
register. This avoids a potential race where new MSI bits may be set
on the ISTATUS_MSI register after it was read and be missed when the
MSI bit in the ISTATUS_LOCAL register is cleared.
Looks good, thank you!
Hmm, there's now a response saying that the proposed commit message is
fine and one saying it isn't. Which is it?
And speaking of that, I looked at all the users of
irq_set_chained_handler_and_data() in drivers/pci. All the handlers
except mc_handle_intx() and mc_handle_msi() call chained_irq_enter()
and chained_irq_exit().
Are mc_handle_intx() and mc_handle_msi() just really special, or is
this a mistake?
That's just a bug. On the right HW, this would just result in lost
interrupts.
Separate issue, separate patch. Do you want them in a series or as
another standalone patch?
Agreed, should be a separate patch. Doesn't need to be a series
unless that patch only applies correctly on top of this one.
Cool, just sent one:
https://lore.kernel.org/linux-pci/20220511095504.2273799-1-conor.dooley@xxxxxxxxxxxxx/
Thanks,
Conor.
