From 89e7eddece6140020749932f9647a6068cc0d56d Mon Sep 17 00:00:00 2001 From: Arun Kumar Neelakantam Date: Wed, 22 Jan 2020 13:54:13 +0530 Subject: 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 Link: https://lore.kernel.org/r/1579681454-1229-1-git-send-email-aneela@codeaurora.org Signed-off-by: Bjorn Andersson --- drivers/soc/qcom/qcom_aoss.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/soc') diff --git a/drivers/soc/qcom/qcom_aoss.c b/drivers/soc/qcom/qcom_aoss.c index fe79661d28cb..f43a2e07ee83 100644 --- a/drivers/soc/qcom/qcom_aoss.c +++ b/drivers/soc/qcom/qcom_aoss.c @@ -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, -- cgit