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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 23329C49EA4 for ; Wed, 23 Jun 2021 12:03:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 074B761076 for ; Wed, 23 Jun 2021 12:03:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230241AbhFWMFT (ORCPT ); Wed, 23 Jun 2021 08:05:19 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:17141 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230163AbhFWMFS (ORCPT ); Wed, 23 Jun 2021 08:05:18 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1624449781; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=TZy3QLobESFBPo4zqXB+Lm4NnttlJStnDUEdgvJ5AMs=; b=rjZdD61tea1se5uj+aTQTZ3itgDSBB2sRDtHbdXT9c+XvaLlzzt3G4Ykqko4fPML0hrb5byk /bvblS14cbyHrh1IzNs23+K/nBEJQRFW2ElLAK9+9mCNQmgdt+oHvHeyO1x7LAH2Z9T0xA7y +PAiv/V2DGccBxPQ1JXnx4RzOjs= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyJlNmU5NiIsICJsaW51eC1zY3NpQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n05.prod.us-east-1.postgun.com with SMTP id 60d322f4dc4628fe7eb9e66f (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 23 Jun 2021 12:03:00 GMT Sender: cang=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 8221FC4360C; Wed, 23 Jun 2021 12:02:59 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: cang) by smtp.codeaurora.org (Postfix) with ESMTPSA id 364F4C433D3; Wed, 23 Jun 2021 12:02:58 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 23 Jun 2021 20:02:58 +0800 From: Can Guo To: Bart Van Assche Cc: "Martin K . Petersen" , linux-scsi@vger.kernel.org, "James E.J. Bottomley" , Stanley Chu , Bean Huo , Avri Altman , Jaegeuk Kim , Asutosh Das Subject: Re: [PATCH RFC 4/4] ufs: Make host controller state change handling more systematic In-Reply-To: <20210619005228.28569-5-bvanassche@acm.org> References: <20210619005228.28569-1-bvanassche@acm.org> <20210619005228.28569-5-bvanassche@acm.org> Message-ID: <58b71eb33b331033d04e4830f5e02d5c@codeaurora.org> X-Sender: cang@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi Bart, On 2021-06-19 08:52, Bart Van Assche wrote: > Introduce a function that reports whether or not a controller state > change > is allowed instead of duplicating these checks in every context that > changes the host controller state. This patch includes a behavior > change: > ufshcd_link_recovery() no longer can change the host controller state > from > UFSHCD_STATE_ERROR into UFSHCD_STATE_RESET. > > Cc: Can Guo > Signed-off-by: Bart Van Assche > --- > drivers/scsi/ufs/ufshcd.c | 59 ++++++++++++++++++++++++--------------- > 1 file changed, 36 insertions(+), 23 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index c213daec20f7..a10c8ec28468 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -4070,16 +4070,32 @@ static int ufshcd_uic_change_pwr_mode(struct > ufs_hba *hba, u8 mode) > return ret; > } > > +static bool ufshcd_set_state(struct ufs_hba *hba, enum ufshcd_state > new_state) > +{ > + lockdep_assert_held(hba->host->host_lock); > + > + if (old_state != UFSHCD_STATE_ERROR || new_state == > UFSHCD_STATE_ERROR) > + hba->ufshcd_state = new_state; > + return true; > + } > + return false; > +} > + > int ufshcd_link_recovery(struct ufs_hba *hba) > { > int ret; > unsigned long flags; > + bool proceed; > > spin_lock_irqsave(hba->host->host_lock, flags); > - hba->ufshcd_state = UFSHCD_STATE_RESET; > - ufshcd_set_eh_in_progress(hba); > + proceed = ufshcd_set_state(hba, UFSHCD_STATE_RESET); > + if (proceed) > + ufshcd_set_eh_in_progress(hba); > spin_unlock_irqrestore(hba->host->host_lock, flags); > > + if (!proceed) > + return -EPERM; > + > /* Reset the attached device */ > ufshcd_device_reset(hba); > > @@ -4087,7 +4103,7 @@ int ufshcd_link_recovery(struct ufs_hba *hba) > > spin_lock_irqsave(hba->host->host_lock, flags); > if (ret) > - hba->ufshcd_state = UFSHCD_STATE_ERROR; > + ufshcd_set_state(hba, UFSHCD_STATE_ERROR); > ufshcd_clear_eh_in_progress(hba); > spin_unlock_irqrestore(hba->host->host_lock, flags); > > @@ -5856,15 +5872,17 @@ static inline bool > ufshcd_is_saved_err_fatal(struct ufs_hba *hba) > /* host lock must be held before calling this func */ > static inline void ufshcd_schedule_eh_work(struct ufs_hba *hba) > { > - /* handle fatal errors only when link is not in error state */ > - if (hba->ufshcd_state != UFSHCD_STATE_ERROR) { > - if (hba->force_reset || ufshcd_is_link_broken(hba) || > - ufshcd_is_saved_err_fatal(hba)) > - hba->ufshcd_state = UFSHCD_STATE_EH_SCHEDULED_FATAL; > - else > - hba->ufshcd_state = UFSHCD_STATE_EH_SCHEDULED_NON_FATAL; > + bool proceed; > + > + if (hba->force_reset || ufshcd_is_link_broken(hba) || > + ufshcd_is_saved_err_fatal(hba)) > + proceed = ufshcd_set_state(hba, > + UFSHCD_STATE_EH_SCHEDULED_FATAL); > + else > + proceed = ufshcd_set_state(hba, > + UFSHCD_STATE_EH_SCHEDULED_NON_FATAL); > + if (proceed) > queue_work(hba->eh_wq, &hba->eh_work); > - } > } > > static void ufshcd_clk_scaling_allow(struct ufs_hba *hba, bool allow) > @@ -6017,8 +6035,7 @@ static void ufshcd_err_handler(struct work_struct > *work) > down(&hba->host_sem); > spin_lock_irqsave(hba->host->host_lock, flags); > if (ufshcd_err_handling_should_stop(hba)) { > - if (hba->ufshcd_state != UFSHCD_STATE_ERROR) > - hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL; > + ufshcd_set_state(hba, UFSHCD_STATE_OPERATIONAL); > spin_unlock_irqrestore(hba->host->host_lock, flags); > up(&hba->host_sem); > return; > @@ -6029,8 +6046,7 @@ static void ufshcd_err_handler(struct work_struct > *work) > /* Complete requests that have door-bell cleared by h/w */ > ufshcd_complete_requests(hba); > spin_lock_irqsave(hba->host->host_lock, flags); > - if (hba->ufshcd_state != UFSHCD_STATE_ERROR) > - hba->ufshcd_state = UFSHCD_STATE_RESET; > + ufshcd_set_state(hba, UFSHCD_STATE_RESET); > /* > * A full reset and restore might have happened after preparation > * is finished, double check whether we should stop. > @@ -6163,8 +6179,7 @@ static void ufshcd_err_handler(struct work_struct > *work) > > skip_err_handling: > if (!needs_reset) { > - if (hba->ufshcd_state == UFSHCD_STATE_RESET) > - hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL; State transition to OPERATIONAL should only be from RESET, this is to make sure that we don't miss any new error (fatal or non-fatal) occurs while error handling is running. > + ufshcd_set_state(hba, UFSHCD_STATE_OPERATIONAL); > if (hba->saved_err || hba->saved_uic_err) > dev_err_ratelimited(hba->dev, "%s: exit: saved_err 0x%x > saved_uic_err 0x%x", > __func__, hba->saved_err, hba->saved_uic_err); > @@ -7135,7 +7150,7 @@ static int ufshcd_reset_and_restore(struct > ufs_hba *hba) > */ > scsi_report_bus_reset(hba->host, 0); > if (err) { > - hba->ufshcd_state = UFSHCD_STATE_ERROR; > + ufshcd_set_state(hba, UFSHCD_STATE_ERROR); > hba->saved_err |= saved_err; > hba->saved_uic_err |= saved_uic_err; > } > @@ -7951,7 +7966,7 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, > bool init_dev_params) > unsigned long flags; > ktime_t start = ktime_get(); > > - hba->ufshcd_state = UFSHCD_STATE_RESET; > + ufshcd_set_state(hba, UFSHCD_STATE_RESET); > > ret = ufshcd_link_startup(hba); > if (ret) > @@ -8024,10 +8039,8 @@ static int ufshcd_probe_hba(struct ufs_hba > *hba, bool init_dev_params) > > out: > spin_lock_irqsave(hba->host->host_lock, flags); > - if (ret) > - hba->ufshcd_state = UFSHCD_STATE_ERROR; > - else if (hba->ufshcd_state == UFSHCD_STATE_RESET) > - hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL; State transition to OPERATIONAL should only be from RESET, this is to make sure that we don't miss any new error (fatal or non-fatal) occurs during re-probe. Thanks, Can Guo. > + ufshcd_set_state(hba, ret ? UFSHCD_STATE_ERROR : > + UFSHCD_STATE_OPERATIONAL); > spin_unlock_irqrestore(hba->host->host_lock, flags); > > trace_ufshcd_init(dev_name(hba->dev), ret,