Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751891AbcCAHdR (ORCPT ); Tue, 1 Mar 2016 02:33:17 -0500 Received: from mx2.suse.de ([195.135.220.15]:34463 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750816AbcCAHdQ (ORCPT ); Tue, 1 Mar 2016 02:33:16 -0500 Subject: Re: [PATCH v5 04/15] scsi: ufs: verify hba controller hce reg value To: Yaniv Gardi , James.Bottomley@HansenPartnership.com References: <1456666367-11418-1-git-send-email-ygardi@codeaurora.org> <1456666367-11418-5-git-send-email-ygardi@codeaurora.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, Raviv Shvili , Vinayak Holikatti , "James E.J. Bottomley" , "Martin K. Petersen" From: Hannes Reinecke Message-ID: <56D545AB.1030606@suse.de> Date: Tue, 1 Mar 2016 15:32:59 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1456666367-11418-5-git-send-email-ygardi@codeaurora.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3390 Lines: 94 On 02/28/2016 09:32 PM, Yaniv Gardi wrote: > Sometimes due to hw issues it takes some time to the > host controller register to update. In order to verify the register > has updated, a polling is done until its value is set. > > In addition the functions ufshcd_hba_stop() and > ufshcd_wait_for_register() was updated with an additional input > parameter, indicating the timeout between reads will > be done by sleeping or spinning the cpu. > > Signed-off-by: Raviv Shvili > Signed-off-by: Yaniv Gardi > > --- > drivers/scsi/ufs/ufshcd.c | 53 ++++++++++++++++++++++++++++------------------- > drivers/scsi/ufs/ufshcd.h | 12 +++-------- > 2 files changed, 35 insertions(+), 30 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index 3400ceb..80031e6 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -240,11 +240,13 @@ static inline void ufshcd_disable_irq(struct ufs_hba *hba) > * @val - wait condition > * @interval_us - polling interval in microsecs > * @timeout_ms - timeout in millisecs > + * @can_sleep - perform sleep or just spin > * > * Returns -ETIMEDOUT on error, zero on success > */ > -static int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask, > - u32 val, unsigned long interval_us, unsigned long timeout_ms) > +int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask, > + u32 val, unsigned long interval_us, > + unsigned long timeout_ms, bool can_sleep) > { > int err = 0; > unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms); > @@ -253,9 +255,10 @@ static int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask, > val = val & mask; > > while ((ufshcd_readl(hba, reg) & mask) != val) { > - /* wakeup within 50us of expiry */ > - usleep_range(interval_us, interval_us + 50); > - > + if (can_sleep) > + usleep_range(interval_us, interval_us + 50); > + else > + udelay(interval_us); > if (time_after(jiffies, timeout)) { > if ((ufshcd_readl(hba, reg) & mask) != val) > err = -ETIMEDOUT; > @@ -1459,7 +1462,7 @@ ufshcd_clear_cmd(struct ufs_hba *hba, int tag) > */ > err = ufshcd_wait_for_register(hba, > REG_UTP_TRANSFER_REQ_DOOR_BELL, > - mask, ~mask, 1000, 1000); > + mask, ~mask, 1000, 1000, true); > > return err; > } > @@ -2815,6 +2818,23 @@ out: > } > > /** > + * ufshcd_hba_stop - Send controller to reset state > + * @hba: per adapter instance > + * @can_sleep: perform sleep or just spin > + */ > +static inline void ufshcd_hba_stop(struct ufs_hba *hba, bool can_sleep) > +{ > + int err; > + > + ufshcd_writel(hba, CONTROLLER_DISABLE, REG_CONTROLLER_ENABLE); > + err = ufshcd_wait_for_register(hba, REG_CONTROLLER_ENABLE, > + CONTROLLER_ENABLE, CONTROLLER_DISABLE, > + 10, 1, can_sleep); > + if (err) > + dev_err(hba->dev, "%s: Controller disable failed\n", __func__); > +} > + Shouldn't you return an error here? If the controller disable failed you probably need a hard reset or something, otherwise I would assume that every other command from that point on will not work as expected. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N?rnberg GF: J. Hawn, J. Guild, F. Imend?rffer, HRB 16746 (AG N?rnberg)