Hi Niklas,
On 2025/01/31 21:10, Niklas Cassel wrote:
On Fri, Jan 31, 2025 at 07:16:54PM +0900, Kunihiko Hayashi wrote:
Hi Niklas,
On 2025/01/29 20:58, Niklas Cassel wrote:
On Tue, Jan 28, 2025 at 08:02:31PM +0530, Manivannan Sadhasivam wrote:
On Wed, Jan 22, 2025 at 11:24:46AM +0900, Kunihiko Hayashi wrote:
There are two variables that indicate the interrupt type to be
used
in the next test execution, "irq_type" as global and
test->irq_type.
The global is referenced from pci_endpoint_test_get_irq() to
preserve
the current type for ioctl(PCITEST_GET_IRQTYPE).
The type set in this function isn't reflected in the global
"irq_type",
so ioctl(PCITEST_GET_IRQTYPE) returns the previous type.
As a result, the wrong type will be displayed in "pcitest" as
follows:
# pcitest -i 0
SET IRQ TYPE TO LEGACY: OKAY
# pcitest -I
GET IRQ TYPE: MSI
Fix this issue by propagating the current type to the global
"irq_type".
This is becoming a nuisance. I think we should get rid of the global
'irq_type'
and just stick to the one that is configurable using IOCTL command.
Even
if the
user has configured the global 'irq_type' it is bound to change with
IOCTL
command.
+1
After fixing the issue described in this patch,
we can replace with a new member of 'struct pci_endpoint_test' instead.
Sorry, but I don't understand what you mean here.
You want this patch to be applied.
Then you want to add a new struct member to struct pci_endpoint_test?
struct pci_endpoint_test already has a struct member named irq_type,
so why do you want to add a new member?
Sorry for confusion.
The internal state (test->irq_type) has the state IRQ_TYPE_UNDEFINED and
the global irq_type doesn't. Then I've thought that ioctl(GET_IRQTYPE)
should not return UNDEFINED state.
However, ioctl(GET_IRQTYPE) can return with an error if the state is
UNDEFINED. This is new behavior, but not inconsistent.
So the additional irq_type is no longer necessary.
Like Mani suggested, I think it would be nice if we could remove the
global irq_type kernel module parameter, and change so that
PCITEST_GET_IRQTYPE returns test->irq_type.
I see.
I'll add new patch to remove the global irq_type and replace with
test->irq_type.
Note that your series does not apply to pci/next, and needs to be rebased.
(It conflicts with f26d37ee9bda ("misc: pci_endpoint_test: Fix IOCTL
return value"))
Yes, I've confirmed the conflict and I'll rebase it next.
But I also don't like how since we migrated to selftests:
READ_TEST / WRITE_TEST / COPY_TEST unconditionally call
ioctl(PCITEST_SET_IRQTYPE, MSI) before doing their thing.
I think that it's better to prepare new patch series.
Here, I was pointing out what I think is a regression with the
migration to selftests. (Which is unrelated to this series.)
I do suggest a way to improve things futher down (introducing a
PCITEST_SET_IRQTYPE, AUTO), but I don't think that you need to be
the one implementing this suggestion, since you did not introduce
this regression.
Okay, I expect another topic after we remove the global variables.
Will this cause the test case to fail for platforms that only support
MSI-X?
(See e.g. dwc/pci-layerscape-ep.c where this could be the case.)
Sure, before, in pcitest.sh, we would do:
pcitest -i 2
pcitest -x $msix
pcitest -i 1
pcitest -r -s 1
pcitest -r -s 1024
pcitest -r -s 1025
pcitest -r -s 1024000
pcitest -r -s 1024001
Which would probably print an error if:
pcitest -i 1
failed.
but the READ_TEST / WRITE_TEST / COPY_TEST tests themselves
would not fail.
Perhaps we should rethink this, and introduce a new
PCITEST_SET_IRQTYPE, AUTO
I would be fine if
READ_TEST / WRITE_TEST / COPY_TEST
called PCITEST_SET_IRQTYPE, AUTO
before doing their thing.
How I suggest PCITEST_SET_IRQTYPE, AUTO
would work:
Since we now have capabilties merged:
https://lore.kernel.org/linux-pci/20241203063851.695733-4-cassel@xxxxxxxxx
g/
Add epc_features->msi_capable and epc->features->msix_capable
as two new bits in the PCI_ENDPOINT_TEST_CAPS register.
If PCITEST_SET_IRQTYPE, AUTO:
if EP CAP has msi_capable set: set IRQ type MSI
else if EP CAP has msix_capable set: set IRQ type MSI-X
else: set legacy/INTx
There is something ambiguous about the behavior for me.
The test->irq_type has a state "UNDEFINED".
After issueing "Clear IRQ", test->irq_type becomes "UNDEFINED"
currently,
and all tests with IRQs will fail until new test->irq_type is set.
That is fine, no?
If a user calls PCITEST_CLEAR_IRQ without doing a PCITEST_SET_IRQTYPE
afterwards, what else can the tests relying on IRQs to other than fail?
FWIW, tools/testing/selftests/pci_endpoint/pci_endpoint_test.c never does
an ioctl(PCITEST_CLEAR_IRQ).
As mentioned above, PCITEST_GET_IRQTYPE can fail with an error, and
I understand that this will not affect the test.
Thank you,
If SET_IRQTYPE is AUTO, how will test->irq_type be set?
I was thinking something like this:
pci_endpoint_test_set_irq()
{
u32 caps = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_CAPS);
...
if (req_irq_type == IRQ_TYPE_AUTO) {
if (caps & MSI_CAPABLE)
test->irq_type = IRQ_TYPE_MSI;
else if (caps & MSIX_CAPABLE)
test->irq_type = IRQ_TYPE_MSIX;
else
test->irq_type = IRQ_TYPE_INTX;
}
...
}
Kind regards,
Niklas
---
Best Regards
Kunihiko Hayashi
