From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subhash Jadavani Subject: Re: [PATCH v2 05/10] scsi: ufshcd: fix possible unclocked register access Date: Wed, 16 May 2018 14:12:33 -0700 Message-ID: <45d251138fac73f4776eae34d9e36def@codeaurora.org> References: <7f237069f86547afedcbbdf673cf85dfb20d05fa.1525343531.git.asutoshd@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <7f237069f86547afedcbbdf673cf85dfb20d05fa.1525343531.git.asutoshd@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Asutosh Das Cc: cang@codeaurora.org, vivek.gautam@codeaurora.org, rnayak@codeaurora.org, vinholikatti@gmail.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com, linux-mmc@vger.kernel.org, linux-scsi@vger.kernel.org, linux-arm-msm@vger.kernel.org, Venkat Gopalakrishnan , linux-kernel@vger.kernel.org, linux-scsi-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org On 2018-05-03 04:07, Asutosh Das wrote: > From: Subhash Jadavani > > vendor specific setup_clocks ops may depend on clocks managed by ufshcd > driver so if the vendor specific setup_clocks callback is called when > the required clocks are turned off, it results into unclocked register > access. > > This change make sure that required clocks are enabled before vendor > specific setup_clocks callback is called. > > Signed-off-by: Subhash Jadavani > Signed-off-by: Venkat Gopalakrishnan > Signed-off-by: Can Guo > Signed-off-by: Asutosh Das > --- > drivers/scsi/ufs/ufshcd.c | 26 ++++++++++++++++++++------ > 1 file changed, 20 insertions(+), 6 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index 838ba8f0..dfeb194 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -6780,9 +6780,16 @@ static int __ufshcd_setup_clocks(struct ufs_hba > *hba, bool on, > if (list_empty(head)) > goto out; > > - ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE); > - if (ret) > - return ret; > + /* > + * vendor specific setup_clocks ops may depend on clocks managed by > + * this standard driver hence call the vendor specific setup_clocks > + * before disabling the clocks managed here. > + */ > + if (!on) { > + ret = ufshcd_vops_setup_clocks(hba, on, PRE_CHANGE); > + if (ret) > + return ret; > + } > > list_for_each_entry(clki, head, list) { > if (!IS_ERR_OR_NULL(clki->clk)) { > @@ -6806,9 +6813,16 @@ static int __ufshcd_setup_clocks(struct ufs_hba > *hba, bool on, > } > } > > - ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE); > - if (ret) > - return ret; > + /* > + * vendor specific setup_clocks ops may depend on clocks managed by > + * this standard driver hence call the vendor specific setup_clocks > + * after enabling the clocks managed here. > + */ > + if (on) { > + ret = ufshcd_vops_setup_clocks(hba, on, POST_CHANGE); > + if (ret) > + return ret; > + } > > out: > if (ret) { Looks good to me. -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project