From: Douglas Anderson <dianders@chromium.org>
To: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: swboyd@chromium.org, Alex Elder <elder@linaro.org>,
mka@chromium.org, Douglas Anderson <dianders@chromium.org>,
Andy Gross <agross@kernel.org>, Vinod Koul <vkoul@kernel.org>,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] soc: qcom: aoss: qmp_send() can't handle interruptions so stop pretending
Date: Wed, 5 Aug 2020 09:16:11 -0700 [thread overview]
Message-ID: <20200805091141.2.If847565ed7568448c67804f3735d5f8a61eda560@changeid> (raw)
In-Reply-To: <20200805091141.1.I86b3faaecb0d82997b599b1300f879606c71e116@changeid>
The function qmp_send() called wait_event_interruptible_timeout() to
wait for its interrupt. However, this function did not check for
-ERESTARTSYS and assumed that any non-zero return value meant that the
event happened.
While we could try to figure out how to handle interruptions by
figuring out how to cancel and/or undo our transfer in a race-free way
and then communicating this status back to all of our callers, that
seems like a whole lot of complexity. As I understand it the transfer
should happen rather quickly and if we're really hitting the 1 second
timeout we're in deep doggy doodoo anyway. Let's just use the
non-interruptible version of the function and call it good enough.
Found by code inspection. No known test cases expose the problem
described here.
Fixes: 2209481409b7 ("soc: qcom: Add AOSS QMP driver")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
drivers/soc/qcom/qcom_aoss.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/qcom/qcom_aoss.c b/drivers/soc/qcom/qcom_aoss.c
index 818cdf74a267..897f9f1c33ba 100644
--- a/drivers/soc/qcom/qcom_aoss.c
+++ b/drivers/soc/qcom/qcom_aoss.c
@@ -257,8 +257,8 @@ static int qmp_send(struct qmp *qmp, const void *data, size_t len, bool noirq)
time_left = readx_poll_timeout_atomic(qmp_message_empty, qmp,
is_empty, is_empty, 1U, 1000000U);
else
- time_left = wait_event_interruptible_timeout(qmp->event,
- qmp_message_empty(qmp), HZ);
+ time_left = wait_event_timeout(qmp->event, qmp_message_empty(qmp), HZ);
+
if (!time_left) {
dev_err(qmp->dev, "ucore did not ack channel\n");
ret = -ETIMEDOUT;
--
2.28.0.163.g6104cc2f0b6-goog
next prev parent reply other threads:[~2020-08-05 20:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-05 16:16 [PATCH 1/2] soc: qcom: aoss: Don't wait for IRQ if we might be in suspend/resume noirq Douglas Anderson
2020-08-05 16:16 ` Douglas Anderson [this message]
2020-08-05 17:28 ` [PATCH 2/2] soc: qcom: aoss: qmp_send() can't handle interruptions so stop pretending Stephen Boyd
2020-08-05 20:25 ` Doug Anderson
2020-08-05 17:36 ` [PATCH 1/2] soc: qcom: aoss: Don't wait for IRQ if we might be in suspend/resume noirq Stephen Boyd
2020-08-05 20:24 ` Doug Anderson
2020-08-05 23:02 ` Stephen Boyd
2020-08-06 14:34 ` Sibi Sankar
2020-08-06 17:10 ` Doug Anderson
2020-08-06 17:33 ` Sibi Sankar
2020-08-11 21:21 ` Doug Anderson
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