2022-10-19 06:40:22

by Pawel Laszczak

Subject: [PATCH] usb: cdnsp: fix issue with ZLP - added TD_SIZE = 1

Patch modifies the TD_SIZE in TRB before ZLP TRB.
The TD_SIZE in TRB before ZLP TRB must be set to 1 to force
processing ZLP TRB by controller.

Cc: <[email protected]>
Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
Signed-off-by: Pawel Laszczak <[email protected]>
---
drivers/usb/cdns3/cdnsp-ring.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c
index 794e413800ae..4809d0e894bb 100644
--- a/drivers/usb/cdns3/cdnsp-ring.c
+++ b/drivers/usb/cdns3/cdnsp-ring.c
@@ -1765,18 +1765,19 @@ static u32 cdnsp_td_remainder(struct cdnsp_device *pdev,
struct cdnsp_request *preq,
bool more_trbs_coming)
{
- u32 maxp, total_packet_count;
-
- /* One TRB with a zero-length data packet. */
- if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
- trb_buff_len == td_total_len)
- return 0;
+ u32 maxp, total_packet_count, remainder;

maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
total_packet_count = DIV_ROUND_UP(td_total_len, maxp);

/* Queuing functions don't count the current TRB into transferred. */
- return (total_packet_count - ((transferred + trb_buff_len) / maxp));
+ remainder = (total_packet_count - ((transferred + trb_buff_len) / maxp));
+
+ /* Before ZLP driver needs set TD_SIZE=1. */
+ if (!remainder && more_trbs_coming)
+ remainder = 1;
+
+ return remainder;
}

static int cdnsp_align_td(struct cdnsp_device *pdev,
--
2.25.1

2022-10-20 13:41:18

by Peter Chen

Subject: Re: [PATCH] usb: cdnsp: fix issue with ZLP - added TD_SIZE = 1

On 22-10-19 02:07:17, Pawel Laszczak wrote:
> Patch modifies the TD_SIZE in TRB before ZLP TRB.
> The TD_SIZE in TRB before ZLP TRB must be set to 1 to force
> processing ZLP TRB by controller.
>
> Cc: <[email protected]>
> Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
> Signed-off-by: Pawel Laszczak <[email protected]>
> ---
> drivers/usb/cdns3/cdnsp-ring.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c
> index 794e413800ae..4809d0e894bb 100644
> --- a/drivers/usb/cdns3/cdnsp-ring.c
> +++ b/drivers/usb/cdns3/cdnsp-ring.c
> @@ -1765,18 +1765,19 @@ static u32 cdnsp_td_remainder(struct cdnsp_device *pdev,
> struct cdnsp_request *preq,
> bool more_trbs_coming)
> {
> - u32 maxp, total_packet_count;
> -
> - /* One TRB with a zero-length data packet. */
> - if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
> - trb_buff_len == td_total_len)
> - return 0;
> + u32 maxp, total_packet_count, remainder;
>
> maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
> total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
>
> /* Queuing functions don't count the current TRB into transferred. */
> - return (total_packet_count - ((transferred + trb_buff_len) / maxp));
> + remainder = (total_packet_count - ((transferred + trb_buff_len) / maxp));
> +
> + /* Before ZLP driver needs set TD_SIZE=1. */
> + if (!remainder && more_trbs_coming)
> + remainder = 1;

Without ZLP, TD_SIZE = 0 for the last TRB.
With ZLP, TD_SIZE = 1 for current TRB, and TD_SIZE = 0 for the next TRB
(the last zero-length packet) right?

Peter

> +
> + return remainder;
> }
>
> static int cdnsp_align_td(struct cdnsp_device *pdev,
> --
> 2.25.1
>

--

Thanks,
Peter Chen

2022-10-21 06:52:03

by Pawel Laszczak

Subject: RE: [PATCH] usb: cdnsp: fix issue with ZLP - added TD_SIZE = 1

>
>
>On 22-10-19 02:07:17, Pawel Laszczak wrote:
>> Patch modifies the TD_SIZE in TRB before ZLP TRB.
>> The TD_SIZE in TRB before ZLP TRB must be set to 1 to force processing
>> ZLP TRB by controller.
>>
>> Cc: <[email protected]>
>> Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence
>> USBSSP DRD Driver")
>> Signed-off-by: Pawel Laszczak <[email protected]>
>> ---
>> drivers/usb/cdns3/cdnsp-ring.c | 15 ++++++++-------
>> 1 file changed, 8 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/usb/cdns3/cdnsp-ring.c
>> b/drivers/usb/cdns3/cdnsp-ring.c index 794e413800ae..4809d0e894bb
>> 100644
>> --- a/drivers/usb/cdns3/cdnsp-ring.c
>> +++ b/drivers/usb/cdns3/cdnsp-ring.c
>> @@ -1765,18 +1765,19 @@ static u32 cdnsp_td_remainder(struct
>cdnsp_device *pdev,
>> struct cdnsp_request *preq,
>> bool more_trbs_coming)
>> {
>> - u32 maxp, total_packet_count;
>> -
>> - /* One TRB with a zero-length data packet. */
>> - if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
>> - trb_buff_len == td_total_len)
>> - return 0;
>> + u32 maxp, total_packet_count, remainder;
>>
>> maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
>> total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
>>
>> /* Queuing functions don't count the current TRB into transferred. */
>> - return (total_packet_count - ((transferred + trb_buff_len) / maxp));
>> + remainder = (total_packet_count - ((transferred + trb_buff_len) /
>> +maxp));
>> +
>> + /* Before ZLP driver needs set TD_SIZE=1. */
>> + if (!remainder && more_trbs_coming)
>> + remainder = 1;
>
>Without ZLP, TD_SIZE = 0 for the last TRB.
>With ZLP, TD_SIZE = 1 for current TRB, and TD_SIZE = 0 for the next TRB (the
>last zero-length packet) right?

Yes, you have right.

Pawel

>Peter
>
>> +
>> + return remainder;
>> }
>>
>> static int cdnsp_align_td(struct cdnsp_device *pdev,
>> --
>> 2.25.1
>>
>
>--
>
>Thanks,
>Peter Chen

Regards,
Pawel Laszczak

2022-10-22 14:32:07

by Peter Chen

Subject: Re: [PATCH] usb: cdnsp: fix issue with ZLP - added TD_SIZE = 1

On 22-10-21 05:03:25, Pawel Laszczak wrote:
> >
> >
> >On 22-10-19 02:07:17, Pawel Laszczak wrote:
> >> Patch modifies the TD_SIZE in TRB before ZLP TRB.
> >> The TD_SIZE in TRB before ZLP TRB must be set to 1 to force processing
> >> ZLP TRB by controller.
> >>
> >> Cc: <[email protected]>
> >> Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence
> >> USBSSP DRD Driver")
> >> Signed-off-by: Pawel Laszczak <[email protected]>
> >> ---
> >> drivers/usb/cdns3/cdnsp-ring.c | 15 ++++++++-------
> >> 1 file changed, 8 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/usb/cdns3/cdnsp-ring.c
> >> b/drivers/usb/cdns3/cdnsp-ring.c index 794e413800ae..4809d0e894bb
> >> 100644
> >> --- a/drivers/usb/cdns3/cdnsp-ring.c
> >> +++ b/drivers/usb/cdns3/cdnsp-ring.c
> >> @@ -1765,18 +1765,19 @@ static u32 cdnsp_td_remainder(struct
> >cdnsp_device *pdev,
> >> struct cdnsp_request *preq,
> >> bool more_trbs_coming)
> >> {
> >> - u32 maxp, total_packet_count;
> >> -
> >> - /* One TRB with a zero-length data packet. */
> >> - if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
> >> - trb_buff_len == td_total_len)
> >> - return 0;
> >> + u32 maxp, total_packet_count, remainder;
> >>
> >> maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
> >> total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
> >>
> >> /* Queuing functions don't count the current TRB into transferred. */
> >> - return (total_packet_count - ((transferred + trb_buff_len) / maxp));
> >> + remainder = (total_packet_count - ((transferred + trb_buff_len) /
> >> +maxp));
> >> +
> >> + /* Before ZLP driver needs set TD_SIZE=1. */
> >> + if (!remainder && more_trbs_coming)
> >> + remainder = 1;
> >
> >Without ZLP, TD_SIZE = 0 for the last TRB.
> >With ZLP, TD_SIZE = 1 for current TRB, and TD_SIZE = 0 for the next TRB (the
> >last zero-length packet) right?
>
> Yes, you have right.
>

Pawel, With your changes, the return value is 1 for function
cdnsp_queue_ctrl_tx. Without your changes, it is 0, something wrong?

--

Thanks,
Peter Chen

2022-10-24 19:02:47

by Pawel Laszczak

Subject: RE: [PATCH] usb: cdnsp: fix issue with ZLP - added TD_SIZE = 1

>> >
>> >On 22-10-19 02:07:17, Pawel Laszczak wrote:
>> >> Patch modifies the TD_SIZE in TRB before ZLP TRB.
>> >> The TD_SIZE in TRB before ZLP TRB must be set to 1 to force
>> >> processing ZLP TRB by controller.
>> >>
>> >> Cc: <[email protected]>
>> >> Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence
>> >> USBSSP DRD Driver")
>> >> Signed-off-by: Pawel Laszczak <[email protected]>
>> >> ---
>> >> drivers/usb/cdns3/cdnsp-ring.c | 15 ++++++++-------
>> >> 1 file changed, 8 insertions(+), 7 deletions(-)
>> >>
>> >> diff --git a/drivers/usb/cdns3/cdnsp-ring.c
>> >> b/drivers/usb/cdns3/cdnsp-ring.c index 794e413800ae..4809d0e894bb
>> >> 100644
>> >> --- a/drivers/usb/cdns3/cdnsp-ring.c
>> >> +++ b/drivers/usb/cdns3/cdnsp-ring.c
>> >> @@ -1765,18 +1765,19 @@ static u32 cdnsp_td_remainder(struct
>> >cdnsp_device *pdev,
>> >> struct cdnsp_request *preq,
>> >> bool more_trbs_coming)
>> >> {
>> >> - u32 maxp, total_packet_count;
>> >> -
>> >> - /* One TRB with a zero-length data packet. */
>> >> - if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
>> >> - trb_buff_len == td_total_len)
>> >> - return 0;
>> >> + u32 maxp, total_packet_count, remainder;
>> >>
>> >> maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
>> >> total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
>> >>
>> >> /* Queuing functions don't count the current TRB into transferred. */
>> >> - return (total_packet_count - ((transferred + trb_buff_len) / maxp));
>> >> + remainder = (total_packet_count - ((transferred + trb_buff_len) /
>> >> +maxp));
>> >> +
>> >> + /* Before ZLP driver needs set TD_SIZE=1. */
>> >> + if (!remainder && more_trbs_coming)
>> >> + remainder = 1;
>> >
>> >Without ZLP, TD_SIZE = 0 for the last TRB.
>> >With ZLP, TD_SIZE = 1 for current TRB, and TD_SIZE = 0 for the next
>> >TRB (the last zero-length packet) right?
>>
>> Yes, you have right.
>>
>
>Pawel, With your changes, the return value is 1 for function
>cdnsp_queue_ctrl_tx. Without your changes, it is 0, something wrong?
>
Yes you have right.
It does not cause a problem, but it's not according with controller specification.

I posted the fixed version of this patch.

Thanks,
Pawel