Hi, Can you elaborate how this can even happen? Isn't the interrupt aggregation capability should attend for those cases?
Thanks, Avri > -----Original Message----- > From: linux-scsi-ow...@vger.kernel.org [mailto:linux-scsi- > ow...@vger.kernel.org] On Behalf Of Asutosh Das > Sent: Tuesday, January 30, 2018 6:54 AM > To: subha...@codeaurora.org; c...@codeaurora.org; > vivek.gau...@codeaurora.org; rna...@codeaurora.org; > vinholika...@gmail.com; j...@linux.vnet.ibm.com; > martin.peter...@oracle.com > Cc: linux-s...@vger.kernel.org; Venkat Gopalakrishnan > <venk...@codeaurora.org>; Asutosh Das <asuto...@codeaurora.org>; open > list <linux-kernel@vger.kernel.org> > Subject: [PATCH 1/1] scsi: ufs: make sure all interrupts are processed > > From: Venkat Gopalakrishnan <venk...@codeaurora.org> > > 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 <venk...@codeaurora.org> > Signed-off-by: Asutosh Das <asuto...@codeaurora.org> > --- > 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 > 8af2af3..58d81de 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -5357,19 +5357,30 @@ 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; > } > -- > Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, > Inc. > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux > Foundation Collaborative Project.
