From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B6E5C433DB for ; Thu, 7 Jan 2021 06:51:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41E35230F9 for ; Thu, 7 Jan 2021 06:51:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726616AbhAGGvs (ORCPT ); Thu, 7 Jan 2021 01:51:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:52530 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725893AbhAGGvr (ORCPT ); Thu, 7 Jan 2021 01:51:47 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 41B8122E00; Thu, 7 Jan 2021 06:51:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610002266; bh=YaDpg+eHj314ji06DzIC9dWK/fl5zkfbM6BL9kqoBlM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Q+3NZgFZDfSxw1d9XazAN8giaFrFZ2r4XSa9/4MBDVFFUgSTDpWgYix8miSB0/Blh lcWLYblOFGzxFmtiqBvPN3Un9PkIEBAJY7/GhIe64LCBwRiV8X4iI66rcYHOnKw7ZC ZX6nd/OCoSWx+TsoGIs/Cgi9u8AVR5drZYLccvex5gPPPson/F+HOBbwtiVkonGgki OJltGQvdWAtnnB5Wcd5Chla2ObYrSBIGvMfIiqGqF8nogiEsS2k57r+pXd79XPLQnx jkBpvGeB55lPYz71xZ+6P/KLZIdJSmow1DNsYyaIXOoJTfj9O5/V9wc9vu3Obp6RUH rWqhAuIThIJvg== Date: Wed, 6 Jan 2021 22:51:04 -0800 From: Jaegeuk Kim To: Can Guo Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, kernel-team@android.com, alim.akhtar@samsung.com, avri.altman@wdc.com, bvanassche@acm.org, martin.petersen@oracle.com, stanley.chu@mediatek.com Subject: Re: [PATCH v3 2/2] scsi: ufs: handle LINERESET with correct tm_cmd Message-ID: References: <20210106214109.44041-1-jaegeuk@kernel.org> <20210106214109.44041-3-jaegeuk@kernel.org> <163fae07a94933230e0432e2ca584040@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <163fae07a94933230e0432e2ca584040@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/07, Can Guo wrote: > On 2021-01-07 05:41, Jaegeuk Kim wrote: > > From: Jaegeuk Kim > > > > This fixes a warning caused by wrong reserve tag usage in > > __ufshcd_issue_tm_cmd. > > > > WARNING: CPU: 7 PID: 7 at block/blk-core.c:630 blk_get_request+0x68/0x70 > > WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82 > > blk_mq_get_tag+0x438/0x46c > > > > And, in ufshcd_err_handler(), we can avoid to send tm_cmd before > > aborting > > outstanding commands by waiting a bit for IO completion like this. > > > > __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out > > > > Would you mind add a Fixes tag? Ok. > > > Signed-off-by: Jaegeuk Kim > > --- > > drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++---- > > 1 file changed, 32 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > > index 1678cec08b51..47fc8da3cbf9 100644 > > --- a/drivers/scsi/ufs/ufshcd.c > > +++ b/drivers/scsi/ufs/ufshcd.c > > @@ -44,6 +44,9 @@ > > /* Query request timeout */ > > #define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */ > > > > +/* LINERESET TIME OUT */ > > +#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */ > > + > > /* Task management command timeout */ > > #define TM_CMD_TIMEOUT 100 /* msecs */ > > > > @@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct > > *work) > > * check if power mode restore is needed. > > */ > > if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) { > > + ktime_t start = ktime_get(); > > + > > hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR; > > if (!hba->saved_uic_err) > > hba->saved_err &= ~UIC_ERROR; > > @@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct work_struct > > *work) > > if (ufshcd_is_pwr_mode_restore_needed(hba)) > > needs_restore = true; > > spin_lock_irqsave(hba->host->host_lock, flags); > > + /* Wait for IO completion to avoid aborting IOs */ > > + while (hba->outstanding_reqs) { > > + ufshcd_complete_requests(hba); > > + spin_unlock_irqrestore(hba->host->host_lock, flags); > > + schedule(); > > + spin_lock_irqsave(hba->host->host_lock, flags); > > + if (ktime_to_ms(ktime_sub(ktime_get(), start)) > > > + LINERESET_IO_TIMEOUT_MS) { > > + dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n", > > + __func__, hba->outstanding_reqs); > > + break; > > + } > > + } > > + > > if (!hba->saved_err && !needs_restore) > > goto skip_err_handling; > > } > > @@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void > > *__hba) > > intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS); > > } > > > > - if (enabled_intr_status && retval == IRQ_NONE) { > > - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n", > > - __func__, intr_status); > > + if (enabled_intr_status && retval == IRQ_NONE && > > + !ufshcd_eh_in_progress(hba)) { > > + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x, > > 0x%08x)\n", > > + __func__, > > + intr_status, > > + hba->ufs_stats.last_intr_status, > > + enabled_intr_status); > > ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: "); > > } > > > > @@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba > > *hba, > > * Even though we use wait_event() which sleeps indefinitely, > > * the maximum wait time is bounded by %TM_CMD_TIMEOUT. > > */ > > - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED); > > + req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED | > > + BLK_MQ_REQ_NOWAIT); > > Sorry that I didn't pay much attention to this part of code before. > May I know why must we use the BLK_MQ_REQ_RESERVED flag? What I understood is the reserved tag is used when aborting outstanding IOs when all the 32 tags were used. > > Thanks, > Can Guo. > > > + if (IS_ERR(req)) > > + return PTR_ERR(req); > > + > > req->end_io_data = &wait; > > free_slot = req->tag; > > WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs); > > @@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void > > __iomem *mmio_base, unsigned int irq) > > > > hba->tmf_tag_set = (struct blk_mq_tag_set) { > > .nr_hw_queues = 1, > > + .reserved_tags = 1, > > If we give reserved_tags as 1 and always ask for a tm requst with > BLK_MQ_REQ_RESERVED flag set, then the tag shall only be allocated > from the reserved sbitmap_queue, whose depth is set to 1 here. > UFS supports tm queue depth as 8, but here is allowing only one tm > req at a time. Why? Please correct me if my understanding is wrong. I couldn't find tm can be issued in parallel, so thought it was issued one at a time. If we set 8, then we can use 24 for IOs, IIUC. Please correct me as well. I'm still trying to understand the flow. > > Thanks, > Can Guo. > > > .queue_depth = hba->nutmrs, > > .ops = &ufshcd_tmf_ops, > > .flags = BLK_MQ_F_NO_SCHED,