soc: qcom: aoss: remove spurious IRQF_ONESHOT flags
authorDaniel Thompson <daniel.thompson@linaro.org>
Thu, 27 Jan 2022 17:35:54 +0000 (17:35 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 8 Apr 2022 12:23:15 +0000 (14:23 +0200)
[ Upstream commit 8030cb9a55688c1339edd284d9d6ce5f9fc75160 ]

Quoting the header comments, IRQF_ONESHOT is "Used by threaded interrupts
which need to keep the irq line disabled until the threaded handler has
been run.". When applied to an interrupt that doesn't request a threaded
irq then IRQF_ONESHOT has a lesser known (undocumented?) side effect,
which it to disable the forced threading of the irq. For "normal" kernels
(without forced threading) then, if there is no thread_fn, then
IRQF_ONESHOT is a nop.

In this case disabling forced threading is not appropriate for this driver
because it calls wake_up_all() and this API cannot be called from
no-thread interrupt handlers on PREEMPT_RT systems (deadlock risk, triggers
sleeping-while-atomic warnings).

Fix this by removing IRQF_ONESHOT.

Fixes: 2209481409b7 ("soc: qcom: Add AOSS QMP driver")
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
[bjorn: Added Fixes tag]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220127173554.158111-1-daniel.thompson@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/soc/qcom/qcom_aoss.c

index 536c3e4..a0659cf 100644 (file)
@@ -548,7 +548,7 @@ static int qmp_probe(struct platform_device *pdev)
        }
 
        irq = platform_get_irq(pdev, 0);
-       ret = devm_request_irq(&pdev->dev, irq, qmp_intr, IRQF_ONESHOT,
+       ret = devm_request_irq(&pdev->dev, irq, qmp_intr, 0,
                               "aoss-qmp", qmp);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to request interrupt\n");