Add a write memory barrier to make sure descriptors prepared are actually written to memory before ringing the doorbell. We have also added the write memory barrier after ringing the doorbell register so that controller sees the new request immediately. Signed-off-by: Gilad Broner <gbroner@xxxxxxxxxxxxxx> Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx> Signed-off-by: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx> --- drivers/scsi/ufs/ufshcd.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 298511a..024cc86 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -833,6 +833,8 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag) ufshcd_clk_scaling_start_busy(hba); __set_bit(task_tag, &hba->outstanding_reqs); ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL); + /* Make sure that doorbell is committed immediately */ + wmb(); } /** @@ -1418,6 +1420,8 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) goto out; } + /* Make sure descriptors are ready before ringing the doorbell */ + wmb(); /* issue command to the controller */ spin_lock_irqsave(hba->host->host_lock, flags); ufshcd_send_command(hba, tag); @@ -1627,6 +1631,8 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, hba->dev_cmd.complete = &wait; + /* Make sure descriptors are ready before ringing the doorbell */ + wmb(); spin_lock_irqsave(hba->host->host_lock, flags); ufshcd_send_command(hba, tag); spin_unlock_irqrestore(hba->host->host_lock, flags); -- 1.8.5.2 -- QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
