Hi Niklas,
On 2025/02/11 1:30, Niklas Cassel wrote:
On Mon, Feb 10, 2025 at 04:58:11PM +0900, Kunihiko Hayashi wrote:
The global variable "irq_type" preserves the current value of
ioctl(GET_IRQTYPE), however, it's enough to use test->irq_type.
Remove the variable, and replace with test->irq_type.
I think the commit message is missing the biggest point.
ioctl(SET_IRQTYPE) sets test->irq_type.
PCITEST_WRITE/PCITEST_READ/PCITEST_COPY all use test->irq_type when
writing the PCI_ENDPOINT_TEST_IRQ_TYPE register in test_reg_bar.
The endpoint function driver (pci-epf-test) will look at
PCI_ENDPOINT_TEST_IRQ_TYPE register in test_reg_bar when determining
which type of IRQ it should raise.
This means that the kernel module parameter is basically useless,
since it is unused if anyone has called ioctl(SET_IRQTYPE).
Both the old pcitest.sh and the new pci_endpoint_test kselftest call
ioctl(SET_IRQTYPE), so in practice the irq_type kernel module parameter
is dead code.
Thank you for pointing out.
Surely, global "irq_type" is only used for return value of ioctl(GET_IRQTYPE).
It isn't used in the test case, and the test is completed with test->irq_type
and the register.
I'll add this point to the explanation.
The ioctl(GET_IRQTYPE) returns an error if test->irq_type has
IRQ_TYPE_UNDEFINED.
Suggested-by: Niklas Cassel <cassel@xxxxxxxxxx>
Suggested-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
---
drivers/misc/pci_endpoint_test.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/misc/pci_endpoint_test.c
b/drivers/misc/pci_endpoint_test.c
index 6a0972e7674f..8d98cd18634d 100644
--- a/drivers/misc/pci_endpoint_test.c
+++ b/drivers/misc/pci_endpoint_test.c
@@ -100,10 +100,6 @@ static bool no_msi;
module_param(no_msi, bool, 0444);
MODULE_PARM_DESC(no_msi, "Disable MSI interrupt in pci_endpoint_test");
Considering that you are removing the irq_type kernel module parameter,
it doesn't make sense to keep the no_msi kernel module parameter IMO.
The exact same argument for why we are removing irq_type, can be made for
no_msi.
Agreed.
Even if chip doesn't have MSI, test->irq_type starts with IRQ_TYPE_UNDEFINED
and will be changed with ioctl(SET_IRQTYPE).
"no_msi" can also be removed.
Thank you,
---
Best Regards
Kunihiko Hayashi
