Commit 89e7edde authored Jan 22, 2020 by Arun Kumar Neelakantam Committed by Bjorn Andersson Feb 13, 2020

soc: qcom: aoss: Read back before triggering the IRQ

In some device memory used by msm_qmp, there can be an early ack of a
write to memory succeeding. This may cause the outgoing interrupt to be
triggered before the msgram reflects the write.

Add a readback to ensure the data is flushed to device memory before
triggering the ipc interrupt.

Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Link: https://lore.kernel.org/r/1579681454-1229-1-git-send-email-aneela@codeaurora.org

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

parent df636eea

drivers/soc/qcom/qcom_aoss.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -225,6 +225,7 @@ static bool qmp_message_empty(struct qmp *qmp)
		static int qmp_send(struct qmp qmp, const void data, size_t len)
		{
		long time_left;
		size_t tlen;
		int ret;

		if (WARN_ON(len + sizeof(u32) > qmp->size))
		@@ -239,6 +240,9 @@ static int qmp_send(struct qmp qmp, const void data, size_t len)
		__iowrite32_copy(qmp->msgram + qmp->offset + sizeof(u32),
		data, len / sizeof(u32));
		writel(len, qmp->msgram + qmp->offset);

		/* Read back len to confirm data written in message RAM */
		tlen = readl(qmp->msgram + qmp->offset);
		qmp_kick(qmp);

		time_left = wait_event_interruptible_timeout(qmp->event,