On 22-10-24 10:04:35, 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: <stable@xxxxxxxxxxxxxxx>
> Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
>
> ---
> Changelog:
> v2:
> - returned value for last TRB must be 0
>
> drivers/usb/cdns3/cdnsp-ring.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c
> index 04dfcaa08dc4..aa79bce89d8a 100644
> --- a/drivers/usb/cdns3/cdnsp-ring.c
> +++ b/drivers/usb/cdns3/cdnsp-ring.c
> @@ -1769,8 +1769,13 @@ static u32 cdnsp_td_remainder(struct cdnsp_device *pdev,
>
> /* One TRB with a zero-length data packet. */
> if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
> - trb_buff_len == td_total_len)
> + trb_buff_len == td_total_len) {
> + /* Before ZLP driver needs set TD_SIZE=1. */
> + if (more_trbs_coming)
> + return 1;
> +
> return 0;
> + }
Does that fix the issue you want at bulk transfer, which has zero-length
packet at the last packet? It seems not align with your previous fix.
Would you mind explaining more?
>
> maxp = usb_endpoint_maxp(preq->pep->endpoint.desc);
> total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
> --
> 2.25.1
>
--
Thanks,
Peter Chen
