From 897efe628d7e0da76c7b20833a7efbd6a4f082d6 Mon Sep 17 00:00:00 2001 From: Yaniv Gardi Date: Mon, 1 Feb 2016 15:02:48 +0200 Subject: [PATCH] scsi: ufs: add missing memory barriers Performing several writes to UFS host controller registers has no guarantee of ordering, so we must make sure register writes to setup request list base address etc. are performed before the run/stop register is enabled. In addition, when setting up a task request, we must make sure the updating of descriptors takes places before ringing the doorbell, similarly to setting up a transfer request. Reviewed-by: Dolev Raviv Signed-off-by: Gilad Broner Signed-off-by: Yaniv Gardi Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufshcd.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a1e9d82716a6..1893a14f231e 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -400,11 +400,9 @@ static inline int ufshcd_get_lists_status(u32 reg) * 1 UTRLRDY * 2 UTMRLRDY * 3 UCRDY - * 4 HEI - * 5 DEI - * 6-7 reserved + * 4-7 reserved */ - return (((reg) & (0xFF)) >> 1) ^ (0x07); + return ((reg & 0xFF) >> 1) ^ 0x07; } /** @@ -2724,7 +2722,7 @@ out: * To bring UFS host controller to operational state, * 1. Enable required interrupts * 2. Configure interrupt aggregation - * 3. Program UTRL and UTMRL base addres + * 3. Program UTRL and UTMRL base address * 4. Configure run-stop-registers * * Returns 0 on success, non-zero value on failure @@ -2753,9 +2751,14 @@ static int ufshcd_make_hba_operational(struct ufs_hba *hba) ufshcd_writel(hba, upper_32_bits(hba->utmrdl_dma_addr), REG_UTP_TASK_REQ_LIST_BASE_H); + /* + * Make sure base address and interrupt setup are updated before + * enabling the run/stop registers below. + */ + wmb(); + /* * UCRDY, UTMRLDY and UTRLRDY bits must be 1 - * DEI, HEI bits must be 0 */ reg = ufshcd_readl(hba, REG_CONTROLLER_STATUS); if (!(ufshcd_get_lists_status(reg))) { @@ -3918,6 +3921,10 @@ static int ufshcd_issue_tm_cmd(struct ufs_hba *hba, int lun_id, int task_id, /* send command to the controller */ __set_bit(free_slot, &hba->outstanding_tasks); + + /* Make sure descriptors are ready before ringing the task doorbell */ + wmb(); + ufshcd_writel(hba, 1 << free_slot, REG_UTP_TASK_REQ_DOOR_BELL); spin_unlock_irqrestore(host->host_lock, flags); -- 2.20.1