diff options
| author | Bhanu Seshu Kumar Valluri <bhanuseshukumar@gmail.com> | 2025-10-14 08:11:09 +0530 |
|---|---|---|
| committer | Manivannan Sadhasivam <mani@kernel.org> | 2025-10-26 21:20:24 +0530 |
| commit | 25423cda145f9ed6ee4a72d9f2603ac2a4685e74 (patch) | |
| tree | 66c9b21c902a7d8cb42715d1fde6e860994bf7d1 | |
| parent | 3a8660878839faadb4f1a6dd72c3179c1df56787 (diff) | |
PCI: endpoint: pci-epf-test: Fix sleeping function being called from atomic context
When Root Complex (RC) triggers a Doorbell interrupt to Endpoint (EP), it
triggers the below warning in the EP:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:271
Call trace:
__might_resched+0x130/0x158
__might_sleep+0x70/0x88
mutex_lock+0x2c/0x80
pci_epc_get_msi+0x78/0xd8
pci_epf_test_raise_irq.isra.0+0x74/0x138
pci_epf_test_doorbell_handler+0x34/0x50
The BUG arises because the EP's pci_epf_test_doorbell_handler() which is
running in the hard IRQ context is making an indirect call to
pci_epc_get_msi(), which uses mutex inside.
To fix the issue, convert the hard IRQ handler to a threaded IRQ handler to
allow it to call functions that can sleep during bottom half execution.
Also, register the threaded IRQ handler with IRQF_ONESHOT to keep the
interrupt line disabled until the threaded IRQ handler completes execution.
Fixes: eff0c286aa91 ("PCI: endpoint: pci-epf-test: Add doorbell test support")
Signed-off-by: Bhanu Seshu Kumar Valluri <bhanuseshukumar@gmail.com>
[mani: reworded description a bit]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20251014024109.42287-1-bhanuseshukumar@gmail.com
| -rw-r--r-- | drivers/pci/endpoint/functions/pci-epf-test.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c index 31617772ad51..b05e8db575c3 100644 --- a/drivers/pci/endpoint/functions/pci-epf-test.c +++ b/drivers/pci/endpoint/functions/pci-epf-test.c @@ -730,8 +730,9 @@ static void pci_epf_test_enable_doorbell(struct pci_epf_test *epf_test, if (bar < BAR_0) goto err_doorbell_cleanup; - ret = request_irq(epf->db_msg[0].virq, pci_epf_test_doorbell_handler, 0, - "pci-ep-test-doorbell", epf_test); + ret = request_threaded_irq(epf->db_msg[0].virq, NULL, + pci_epf_test_doorbell_handler, IRQF_ONESHOT, + "pci-ep-test-doorbell", epf_test); if (ret) { dev_err(&epf->dev, "Failed to request doorbell IRQ: %d\n", |