[PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[DooHyun Hwang]

It is found that is UFS device may take longer than 500ms(50ms * 10times)
to respond to NOP_OUT command.

The NOP_OUT command timeout was total 500ms that is from
a timeout value of 50ms(defined by NOP_OUT_TIMEOUT)
with 10 retries(defined by NOP_OUT_RETRIES)

This change increase the NOP_OUT command timeout to total 1000ms
by changing timeout value to 100ms(NOP_OUT_TIMEOUT)

Signed-off-by: DooHyun Hwang <dh0421.hwang@samsung.com>
---
 drivers/ufs/core/ufshcd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index cd404ade48dc..bf5c4620ef6b 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -57,8 +57,8 @@ enum {
 };
 /* NOP OUT retries waiting for NOP IN response */
 #define NOP_OUT_RETRIES    10
-/* Timeout after 50 msecs if NOP OUT hangs without response */
-#define NOP_OUT_TIMEOUT    50 /* msecs */
+/* Timeout after 100 msecs if NOP OUT hangs without response */
+#define NOP_OUT_TIMEOUT    100 /* msecs */
 
 /* Query request retries */
 #define QUERY_REQ_RETRIES 3
-- 
2.48.0

Re: [PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[Bart Van Assche]

On 1/14/25 6:23 PM, DooHyun Hwang wrote:
> It is found that is UFS device may take longer than 500ms(50ms * 10times)
> to respond to NOP_OUT command.
> 
> The NOP_OUT command timeout was total 500ms that is from
> a timeout value of 50ms(defined by NOP_OUT_TIMEOUT)
> with 10 retries(defined by NOP_OUT_RETRIES)
> 
> This change increase the NOP_OUT command timeout to total 1000ms
> by changing timeout value to 100ms(NOP_OUT_TIMEOUT)
> 
> Signed-off-by: DooHyun Hwang <dh0421.hwang@samsung.com>
> ---
>   drivers/ufs/core/ufshcd.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index cd404ade48dc..bf5c4620ef6b 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -57,8 +57,8 @@ enum {
>   };
>   /* NOP OUT retries waiting for NOP IN response */
>   #define NOP_OUT_RETRIES    10
> -/* Timeout after 50 msecs if NOP OUT hangs without response */
> -#define NOP_OUT_TIMEOUT    50 /* msecs */
> +/* Timeout after 100 msecs if NOP OUT hangs without response */
> +#define NOP_OUT_TIMEOUT    100 /* msecs */
>   
>   /* Query request retries */
>   #define QUERY_REQ_RETRIES 3

The above change relies on all device management commands being issued
with the same tag. If a single NOP OUT command may take longer than
500 ms, shouldn't NOP_OUT_TIMEOUT be increased to 1000 ms instead of
100 ms? The number of NOP OUT retries seems high to me and probably can
be reduced?

Thanks,

Bart.

RE: [PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[DooHyun Hwang(황두현/Device S/W Solution Lab.(MX)/삼성전자)]

> On 1/14/25 6:23 PM, DooHyun Hwang wrote:
> > It is found that is UFS device may take longer than 500ms(50ms *
> > 10times) to respond to NOP_OUT command.
> >
> > The NOP_OUT command timeout was total 500ms that is from a timeout
> > value of 50ms(defined by NOP_OUT_TIMEOUT) with 10 retries(defined by
> > NOP_OUT_RETRIES)
> >
> > This change increase the NOP_OUT command timeout to total 1000ms by
> > changing timeout value to 100ms(NOP_OUT_TIMEOUT)
> >
> > Signed-off-by: DooHyun Hwang <dh0421.hwang@samsung.com>
> > ---
> >   drivers/ufs/core/ufshcd.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> > index cd404ade48dc..bf5c4620ef6b 100644
> > --- a/drivers/ufs/core/ufshcd.c
> > +++ b/drivers/ufs/core/ufshcd.c
> > @@ -57,8 +57,8 @@ enum {
> >   };
> >   /* NOP OUT retries waiting for NOP IN response */
> >   #define NOP_OUT_RETRIES    10
> > -/* Timeout after 50 msecs if NOP OUT hangs without response */
> > -#define NOP_OUT_TIMEOUT    50 /* msecs */
> > +/* Timeout after 100 msecs if NOP OUT hangs without response */
> > +#define NOP_OUT_TIMEOUT    100 /* msecs */
> >
> >   /* Query request retries */
> >   #define QUERY_REQ_RETRIES 3
> 
> The above change relies on all device management commands being issued
> with the same tag. If a single NOP OUT command may take longer than
> 500 ms, shouldn't NOP_OUT_TIMEOUT be increased to 1000 ms instead of
> 100 ms? The number of NOP OUT retries seems high to me and probably can be
> reduced?
> 
> Thanks,
> 
> Bart.
I want to keep sending NOP_OUT commands repeatedly to get a response
from the UFS device, as per the existing method. To accommodate this method,
I propose increasing the total timeout duration by increasing the single timeout
value(defined by NOP_OUT_TIMEOUT) from 50ms to 100ms rather than
increasing the timeout value(defined by NOP_OUT_TIMEOUT) from 50ms to 1000ms
or increasing the retry count value(defined by NOP_OUT_RETRIES).

This is time measurement log confirmed on a real device with NOP_OUT_TIMEOUT is 100ms

1. normal operation
[    2.010156] [6:  kworker/u18:0:   76] ufshcd-qcom 1d84000.ufshc: [TEST] ufshcd_verify_dev_init: takes 1271 us, retries = 1 * 100ms.

2. issued log : exceeds 500ms
[    2.524525] [6:  kworker/u17:2:  141] ufshcd-qcom 1d84000.ufshc: [TEST] ufshcd_verify_dev_init: takes 533000 us, retries = 6 * 100ms.

And a certain UFS vendor has confirmed that the response to NOP_OUT command
can be delayed by up to 540ms in certain circumstances on a specific model.

BR,
Thank you.
DooHyun Hwang.

RE: [PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[Avri Altman]

> It is found that is UFS device may take longer than 500ms(50ms * 10times) to
> respond to NOP_OUT command.
> 
> The NOP_OUT command timeout was total 500ms that is from a timeout
> value of 50ms(defined by NOP_OUT_TIMEOUT) with 10 retries(defined by
> NOP_OUT_RETRIES)
> 
> This change increase the NOP_OUT command timeout to total 1000ms by
> changing timeout value to 100ms(NOP_OUT_TIMEOUT)
> 
> Signed-off-by: DooHyun Hwang <dh0421.hwang@samsung.com>
Why not edit hba->nop_out_timeout in the .init vop?
Like some vendors already do.

Thanks,
Avri

> ---
>  drivers/ufs/core/ufshcd.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index
> cd404ade48dc..bf5c4620ef6b 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -57,8 +57,8 @@ enum {
>  };
>  /* NOP OUT retries waiting for NOP IN response */
>  #define NOP_OUT_RETRIES    10
> -/* Timeout after 50 msecs if NOP OUT hangs without response */
> -#define NOP_OUT_TIMEOUT    50 /* msecs */
> +/* Timeout after 100 msecs if NOP OUT hangs without response */
> +#define NOP_OUT_TIMEOUT    100 /* msecs */
> 
>  /* Query request retries */
>  #define QUERY_REQ_RETRIES 3
> --
> 2.48.0
> 

RE: [PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[DooHyun Hwang]

> 
> > It is found that is UFS device may take longer than 500ms(50ms *
> > 10times) to respond to NOP_OUT command.
> >
> > The NOP_OUT command timeout was total 500ms that is from a timeout
> > value of 50ms(defined by NOP_OUT_TIMEOUT) with 10 retries(defined by
> > NOP_OUT_RETRIES)
> >
> > This change increase the NOP_OUT command timeout to total 1000ms by
> > changing timeout value to 100ms(NOP_OUT_TIMEOUT)
> >
> > Signed-off-by: DooHyun Hwang <dh0421.hwang@samsung.com>
> Why not edit hba->nop_out_timeout in the .init vop?
> Like some vendors already do.
> 
> Thanks,
> Avri
> 
Thank you for your suggestion.
I'll fix that in .init vop as you said.

And I'll reject this patch.

BR,
Thank you.
DooHyun Hwang.

> > ---
> >  drivers/ufs/core/ufshcd.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> > index cd404ade48dc..bf5c4620ef6b 100644
> > --- a/drivers/ufs/core/ufshcd.c
> > +++ b/drivers/ufs/core/ufshcd.c
> > @@ -57,8 +57,8 @@ enum {
> >  };
> >  /* NOP OUT retries waiting for NOP IN response */
> >  #define NOP_OUT_RETRIES    10
> > -/* Timeout after 50 msecs if NOP OUT hangs without response */
> > -#define NOP_OUT_TIMEOUT    50 /* msecs */
> > +/* Timeout after 100 msecs if NOP OUT hangs without response */
> > +#define NOP_OUT_TIMEOUT    100 /* msecs */
> >
> >  /* Query request retries */
> >  #define QUERY_REQ_RETRIES 3
> > --
> > 2.48.0
> >

Re: [PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[Bart Van Assche]

On 1/15/25 6:02 PM, DooHyun Hwang(황두현/Device S/W Solution Lab.(MX)/삼성전자) 
wrote:
> I want to keep sending NOP_OUT commands repeatedly to get a response
> from the UFS device, as per the existing method. To accommodate this method,
> I propose increasing the total timeout duration by increasing the single timeout
> value(defined by NOP_OUT_TIMEOUT) from 50ms to 100ms rather than
> increasing the timeout value(defined by NOP_OUT_TIMEOUT) from 50ms to 1000ms
> or increasing the retry count value(defined by NOP_OUT_RETRIES).
> 
> This is time measurement log confirmed on a real device with NOP_OUT_TIMEOUT is 100ms
> 
> 1. normal operation
> [    2.010156] [6:  kworker/u18:0:   76] ufshcd-qcom 1d84000.ufshc: [TEST] ufshcd_verify_dev_init: takes 1271 us, retries = 1 * 100ms.
> 
> 2. issued log : exceeds 500ms
> [    2.524525] [6:  kworker/u17:2:  141] ufshcd-qcom 1d84000.ufshc: [TEST] ufshcd_verify_dev_init: takes 533000 us, retries = 6 * 100ms.
> 
> And a certain UFS vendor has confirmed that the response to NOP_OUT command
> can be delayed by up to 540ms in certain circumstances on a specific model.

Thank you for having provided all this additional information. Because
of the above clarification, feel free to add:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[Bao D. Nguyen]

On 1/16/2025 1:59 AM, DooHyun Hwang wrote:
>>
>>> It is found that is UFS device may take longer than 500ms(50ms *
>>> 10times) to respond to NOP_OUT command.
>>>
>>> The NOP_OUT command timeout was total 500ms that is from a timeout
>>> value of 50ms(defined by NOP_OUT_TIMEOUT) with 10 retries(defined by
>>> NOP_OUT_RETRIES)
>>>
>>> This change increase the NOP_OUT command timeout to total 1000ms by
>>> changing timeout value to 100ms(NOP_OUT_TIMEOUT)
>>>
>>> Signed-off-by: DooHyun Hwang <dh0421.hwang@samsung.com>
>> Why not edit hba->nop_out_timeout in the .init vop?
>> Like some vendors already do.
>>
>> Thanks,
>> Avri
>>
> Thank you for your suggestion.
> I'll fix that in .init vop as you said.
> 
> And I'll reject this patch.
Hi DooHyun Hwang,
Since this is a common issue that multiple platform vendors have to fix 
in their vops, should we fix it in the common code instead?

Reviewed-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>

RE: [PATCH] scsi: ufs: core: increase the NOP_OUT command timeout

[DooHyun Hwang]

On 1/16/2025 8:30 AM, Bao D. Nguyen wrote:
> On 1/16/2025 1:59 AM, DooHyun Hwang wrote:
> >>
> >>> It is found that is UFS device may take longer than 500ms(50ms *
> >>> 10times) to respond to NOP_OUT command.
> >>>
> >>> The NOP_OUT command timeout was total 500ms that is from a timeout
> >>> value of 50ms(defined by NOP_OUT_TIMEOUT) with 10 retries(defined by
> >>> NOP_OUT_RETRIES)
> >>>
> >>> This change increase the NOP_OUT command timeout to total 1000ms by
> >>> changing timeout value to 100ms(NOP_OUT_TIMEOUT)
> >>>
> >>> Signed-off-by: DooHyun Hwang <dh0421.hwang@samsung.com>
> >> Why not edit hba->nop_out_timeout in the .init vop?
> >> Like some vendors already do.
> >>
> >> Thanks,
> >> Avri
> >>
> > Thank you for your suggestion.
> > I'll fix that in .init vop as you said.
> >
> > And I'll reject this patch.
> Hi DooHyun Hwang,
> Since this is a common issue that multiple platform vendors have to fix in
> their vops, should we fix it in the common code instead?
> 
> Reviewed-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>


This is already set to rejected state on patchwork.
Anyway, thank you for the review.

I thought it would be efficient to fix it in the common code.
I don't know which UFS devices have the same problem.

Thank you.
DooHyun Hwang.