From: Avri Altman <Avri.Altman@wdc.com>
To: Can Guo <cang@codeaurora.org>,
"asutoshd@codeaurora.org" <asutoshd@codeaurora.org>,
"nguyenb@codeaurora.org" <nguyenb@codeaurora.org>,
"rnayak@codeaurora.org" <rnayak@codeaurora.org>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>,
"kernel-team@android.com" <kernel-team@android.com>,
"saravanak@google.com" <saravanak@google.com>,
"salyzyn@google.com" <salyzyn@google.com>
Cc: Subhash Jadavani <subhashj@codeaurora.org>,
Alim Akhtar <alim.akhtar@samsung.com>,
Pedro Sousa <pedrom.sousa@synopsys.com>,
"James E.J. Bottomley" <jejb@linux.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Stanley Chu <stanley.chu@mediatek.com>,
Bean Huo <beanhuo@micron.com>,
Tomas Winkler <tomas.winkler@intel.com>,
Venkat Gopalakrishnan <venkatg@codeaurora.org>,
open list <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v4 7/7] scsi: ufs: Fix error handing during hibern8 enter
Date: Thu, 14 Nov 2019 11:06:25 +0000 [thread overview]
Message-ID: <MN2PR04MB699130F410CDE9BFB5815CC0FC710@MN2PR04MB6991.namprd04.prod.outlook.com> (raw)
In-Reply-To: <1573627552-12615-8-git-send-email-cang@codeaurora.org>
>
>
> From: Subhash Jadavani <subhashj@codeaurora.org>
>
> During clock gating (ufshcd_gate_work()), we first put the link hibern8 by
> calling ufshcd_uic_hibern8_enter() and if ufshcd_uic_hibern8_enter() returns
> success (0) then we gate all the clocks.
> Now let’s zoom in to what ufshcd_uic_hibern8_enter() does internally:
> It calls __ufshcd_uic_hibern8_enter() which on detecting the LINERESET,
> initiates the full recovery and puts the link back to highest HS gear and returns
> success (0) to ufshcd_uic_hibern8_enter() which is the issue as link is still in
> active state due to recovery!
> Now ufshcd_uic_hibern8_enter() returns success to ufshcd_gate_work() and
> hence it goes ahead with gating the UFS clock while link is still in active state
> hence I believe controller would raise UIC error interrupts. But when we service
> the interrupt, clocks might have already been disabled!
>
> This change fixes for this by returning failure from
> __ufshcd_uic_hibern8_enter() if recovery succeeds as link is still not in hibern8,
> upon receiving the error ufshcd_hibern8_enter() would initiate retry to put the
> link state back into hibern8.
>
> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> Signed-off-by: Can Guo <cang@codeaurora.org>
> ---
> drivers/scsi/ufs/ufshcd.c | 19 ++++++++++++++-----
> 1 file changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index
> 7a5a904..934c27a 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -3891,15 +3891,24 @@ static int __ufshcd_uic_hibern8_enter(struct
> ufs_hba *hba)
> ktime_to_us(ktime_sub(ktime_get(), start)), ret);
>
> if (ret) {
> + int err;
> +
> dev_err(hba->dev, "%s: hibern8 enter failed. ret = %d\n",
> __func__, ret);
>
> /*
> - * If link recovery fails then return error so that caller
> - * don't retry the hibern8 enter again.
> + * If link recovery fails then return error code (-ENOLINK)
> + * returned ufshcd_link_recovery().
> + * If link recovery succeeds then return -EAGAIN to attempt
> + * hibern8 enter retry again.
You no longer returning -ENOLINK, and either way retrying, regardless of the error code.
Better check that the commit log is still telling the correct story, taking into consideration all those recent fixes and all.
> */
> - if (ufshcd_link_recovery(hba))
> - ret = -ENOLINK;
> + err = ufshcd_link_recovery(hba);
> + if (err) {
> + dev_err(hba->dev, "%s: link recovery failed", __func__);
> + ret = err;
> + } else {
> + ret = -EAGAIN;
> + }
> } else
> ufshcd_vops_hibern8_notify(hba, UIC_CMD_DME_HIBER_ENTER,
> POST_CHANGE); @@ -3913,7 +3922,7 @@
> static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
>
> for (retries = UIC_HIBERN8_ENTER_RETRIES; retries > 0; retries--) {
> ret = __ufshcd_uic_hibern8_enter(hba);
> - if (!ret || ret == -ENOLINK)
> + if (!ret)
> goto out;
> }
> out:
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2019-11-14 11:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1573627552-12615-1-git-send-email-cang@codeaurora.org>
2019-11-13 6:45 ` [PATCH v4 1/7] scsi: ufs: Add device reset in link recovery path Can Guo
2019-11-13 6:45 ` [PATCH v4 2/7] scsi: ufs-qcom: Add reset control support for host controller Can Guo
2019-11-14 9:03 ` Avri Altman
2019-11-15 1:25 ` Can Guo
2019-11-13 6:45 ` [PATCH v4 3/7] scsi: ufs: Fix up auto hibern8 enablement Can Guo
2019-11-14 9:23 ` Avri Altman
2019-11-15 3:33 ` Can Guo
2019-11-13 6:45 ` [PATCH v4 4/7] scsi: ufs: Fix register dump caused sleep in atomic context Can Guo
2019-11-13 6:45 ` [PATCH v4 5/7] scsi: ufs: Fix irq return code Can Guo
2019-11-14 10:43 ` Avri Altman
2019-11-13 6:45 ` [PATCH v4 6/7] scsi: ufs: Abort gating if clock on request is pending Can Guo
2019-11-14 10:46 ` Avri Altman
2019-11-13 6:45 ` [PATCH v4 7/7] scsi: ufs: Fix error handing during hibern8 enter Can Guo
2019-11-14 11:06 ` Avri Altman [this message]
2019-11-15 1:33 ` Can Guo
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