From: Venkat Gopalakrishnan <[email protected]>
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 <[email protected]>
Signed-off-by: Asutosh Das <[email protected]>
---
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.
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: [email protected] [mailto:linux-scsi-
> [email protected]] On Behalf Of Asutosh Das
> Sent: Tuesday, January 30, 2018 6:54 AM
> To: [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected];
> [email protected]
> Cc: [email protected]; Venkat Gopalakrishnan
> <[email protected]>; Asutosh Das <[email protected]>; open
> list <[email protected]>
> Subject: [PATCH 1/1] scsi: ufs: make sure all interrupts are processed
>
> From: Venkat Gopalakrishnan <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Asutosh Das <[email protected]>
> ---
> 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.
On 1/31/2018 1:09 PM, Avri Altman wrote:
> 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: [email protected] [mailto:linux-scsi-
>> [email protected]] On Behalf Of Asutosh Das
>> Sent: Tuesday, January 30, 2018 6:54 AM
>> To: [email protected]; [email protected];
>> [email protected]; [email protected];
>> [email protected]; [email protected];
>> [email protected]
>> Cc: [email protected]; Venkat Gopalakrishnan
>> <[email protected]>; Asutosh Das <[email protected]>; open
>> list <[email protected]>
>> Subject: [PATCH 1/1] scsi: ufs: make sure all interrupts are processed
>>
>> From: Venkat Gopalakrishnan <[email protected]>
>>
>> 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 <[email protected]>
>> Signed-off-by: Asutosh Das <[email protected]>
>> ---
>> 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.
>
Hi
yes - interrupt aggregation makes sense here. But there were some
performance concerns with it; well, I don't have the data to back that
up now though.
However, I can code it up and check it.
Will post it in some time.
-asd
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
Linux Foundation Collaborative Project
On 2/2/2018 8:53 AM, Asutosh Das (asd) wrote:
> On 1/31/2018 1:09 PM, Avri Altman wrote:
>> 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: [email protected] [mailto:linux-scsi-
>>> [email protected]] On Behalf Of Asutosh Das
>>> Sent: Tuesday, January 30, 2018 6:54 AM
>>> To: [email protected]; [email protected];
>>> [email protected]; [email protected];
>>> [email protected]; [email protected];
>>> [email protected]
>>> Cc: [email protected]; Venkat Gopalakrishnan
>>> <[email protected]>; Asutosh Das <[email protected]>; open
>>> list <[email protected]>
>>> Subject: [PATCH 1/1] scsi: ufs: make sure all interrupts are processed
>>>
>>> From: Venkat Gopalakrishnan <[email protected]>
>>>
>>> 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 <[email protected]>
>>> Signed-off-by: Asutosh Das <[email protected]>
>>> ---
>>> 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.
>>
>
> Hi
> yes - interrupt aggregation makes sense here. But there were some
> performance concerns with it; well, I don't have the data to back that
> up now though.
> However, I can code it up and check it.
> Will post it in some time.
>
> -asd
>
Hi Avri,
I went through the UFS HCI - v2.1 spec. Specifically, in sec 7.2.3 it
explicitly mentions that the software should determine if new TRs were
completed since the interrupt status was last read/cleared. This step is
independent of aggregation.
So I think the above implementation makes sense. Please let me know if I
understood your concern correctly.
-asd
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a
Linux Foundation Collaborative Project
> >>> -----Original Message-----
> >>> From: [email protected] [mailto:linux-scsi-
> >>> [email protected]] On Behalf Of Asutosh Das
> >>> Sent: Tuesday, January 30, 2018 6:54 AM
> >>> To: [email protected]; [email protected];
> >>> [email protected]; [email protected];
> >>> [email protected]; [email protected];
> >>> [email protected]
> >>> Cc: [email protected]; Venkat Gopalakrishnan
> >>> <[email protected]>; Asutosh Das <[email protected]>;
> >>> open list <[email protected]>
> >>> Subject: [PATCH 1/1] scsi: ufs: make sure all interrupts are
> >>> processed
> >>>
> >>> From: Venkat Gopalakrishnan <[email protected]>
> >>>
> >>> 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 <[email protected]>
> >>> Signed-off-by: Asutosh Das <[email protected]>
Tested-by: [email protected]
Tested on kirin960 (mate9) and msm8998 (htc11), both where interrupt aggregation is not allowed.
As a side note, I noticed that this patch is part of several patches, fixing some qcom-staff.
Maybe you want to put them all in a patchset?
Thanks,
Avri