diff mbox

[v2,08/10] scsi: ufs: make sure all interrupts are processed

Message ID faa728f587df5372dd78b3d012ed6bf78e92e883.1525343531.git.asutoshd@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Asutosh Das (asd) May 3, 2018, 10:35 a.m. UTC 
From: Venkat Gopalakrishnan <venkatg@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 <venkatg@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

Comments

subhashj@codeaurora.org May 16, 2018, 9:04 p.m. UTC | #1 
On 2018-05-03 03:35, Asutosh Das wrote:
> From: Venkat Gopalakrishnan <venkatg@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 <venkatg@codeaurora.org>
> Signed-off-by: Asutosh Das <asutoshd@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 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 <subhashj@codeaurora.org>
subhashj@codeaurora.org May 16, 2018, 9:14 p.m. UTC | #2 
On 2018-05-03 04:07, Asutosh Das wrote:
> From: Venkat Gopalakrishnan <venkatg@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 <venkatg@codeaurora.org>
> Signed-off-by: Asutosh Das <asutoshd@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 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 <subhashj@codeaurora.org>
diff mbox

Patch

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;
 }