Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753314AbbHUWKz (ORCPT ); Fri, 21 Aug 2015 18:10:55 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:37520 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753274AbbHUWKv (ORCPT ); Fri, 21 Aug 2015 18:10:51 -0400 From: Yaniv Gardi To: robherring2@gmail.com, James.Bottomley@HansenPartnership.com, pebolle@tiscali.nl, hch@infradead.org Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-arm-msm@vger.kernel.org, santoshsy@gmail.com, linux-scsi-owner@vger.kernel.org, subhashj@codeaurora.org, ygardi@codeaurora.org, gbroner@codeaurora.org, draviv@codeaurora.org, Vinayak Holikatti , "James E.J. Bottomley" Subject: [PATCH v1 13/15] scsi: ufs: add missing memory barriers Date: Sat, 22 Aug 2015 01:09:47 +0300 Message-Id: <1440194989-28835-14-git-send-email-ygardi@codeaurora.org> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1440194989-28835-1-git-send-email-ygardi@codeaurora.org> References: <1440194989-28835-1-git-send-email-ygardi@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2618 Lines: 80 Performing several writes to UFS host controller registers has no gurrantee 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. Signed-off-by: Yaniv Gardi --- drivers/scsi/ufs/ufshcd.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 8f17cf5..fef0660 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -401,11 +401,9 @@ 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; } /** @@ -2726,7 +2724,7 @@ 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 @@ -2756,8 +2754,13 @@ static int ufshcd_make_hba_operational(struct ufs_hba *hba) 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))) { @@ -3920,7 +3923,13 @@ 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); + /* Make sure that doorbell is committed immediately */ + wmb(); spin_unlock_irqrestore(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-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/