From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subhash Jadavani Subject: Re: [PATCH v2 08/10] scsi: ufs: make sure all interrupts are processed Date: Wed, 16 May 2018 14:14:04 -0700 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: 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, Venkat Gopalakrishnan , linux-arm-msm@vger.kernel.org, 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: Venkat Gopalakrishnan > > As multiple requests are submitted to the ufs host controller in > parallel there could be instances where the command completion > interrupt arrives later for a request that is already processed > earlier as the corresponding doorbell was cleared when handling > the previous interrupt. Read the interrupt status in a loop after > processing the received interrupt to catch such interrupts and > handle it. > > Signed-off-by: Venkat Gopalakrishnan > Signed-off-by: Asutosh Das > --- > drivers/scsi/ufs/ufshcd.c | 27 +++++++++++++++++++-------- > 1 file changed, 19 insertions(+), 8 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index c35a076..09b7a3f 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -5383,19 +5383,30 @@ static irqreturn_t ufshcd_intr(int irq, void > *__hba) > u32 intr_status, enabled_intr_status; > irqreturn_t retval = IRQ_NONE; > struct ufs_hba *hba = __hba; > + int retries = hba->nutrs; > > spin_lock(hba->host->host_lock); > intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS); > - enabled_intr_status = > - intr_status & ufshcd_readl(hba, REG_INTERRUPT_ENABLE); > > - if (intr_status) > - ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS); > + /* > + * There could be max of hba->nutrs reqs in flight and in worst case > + * if the reqs get finished 1 by 1 after the interrupt status is > + * read, make sure we handle them by checking the interrupt status > + * again in a loop until we process all of the reqs before returning. > + */ > + do { > + enabled_intr_status = > + intr_status & ufshcd_readl(hba, REG_INTERRUPT_ENABLE); > + if (intr_status) > + ufshcd_writel(hba, intr_status, REG_INTERRUPT_STATUS); > + if (enabled_intr_status) { > + ufshcd_sl_intr(hba, enabled_intr_status); > + retval = IRQ_HANDLED; > + } > + > + intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS); > + } while (intr_status && --retries); > > - if (enabled_intr_status) { > - ufshcd_sl_intr(hba, enabled_intr_status); > - retval = IRQ_HANDLED; > - } > spin_unlock(hba->host->host_lock); > return retval; > } Looks good to me. Reviewed-by: Subhash Jadavani -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project