>On Thu, Nov 10, 2022 at 1:38 PM Pawel Laszczak <pawell@xxxxxxxxxxx> >wrote: >> >> >On Mon, Nov 7, 2022 at 1:39 PM Pawel Laszczak <pawell@xxxxxxxxxxx> >> >wrote: >> >> >> >> > >> >> > >> >> >On 22-10-27 08:46:17, Pawel Laszczak wrote: >> >> >> >> >> >> > >> >> >> >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? >> >> >> >> >> >> Value returned by function cdnsp_td_remainder is used as TD_SIZE >> >> >> in TRB. >> >> >> >> >> >> The last TRB in TD should have TD_SIZE=0, so trb for ZLP should >> >> >> have set also TD_SIZE=0. If driver set TD_SIZE=0 on before the >> >> >> last one TRB then the controller stops the transfer and ignore >> >> >> trb for ZLP >> >packet. >> >> >> >> >> >> To fix this, the driver in such case must set TD_SIZE = 1 before >> >> >> the last TRB. >> >> > >> >> > 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; >> >> > + } >> >> > >> >> >How your above fix could return TD_SIZE as 1 for last non-ZLP TRB? >> >> >Which conditions are satisfied? >> >> >> >> For last non-ZLP TRB TD_SIZE should be 0 or 1. >> >> >> >> We have three casess: >> >> 1. >> >> TRB1 - length > 1 >> >> TRb2 - ZLP >> >> >> >> In this case TRB1 should have set TD_SIZE = 1. In this case the condition >> >> if (more_trbs_coming) >> >> return 1; >> >> >> >> returns TD_SIZE=1. In this case more_trb_comming for TRB1 is 1 and >> >> for >> >> TRB2 is 0 >> >> >> > >> >This one is my question. How below condition is true for your case 1: >> > >> > if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) || >> > trb_buff_len == td_total_len) >> >> For TRB1: >> more_trbs_coming = true >> transferred == 0 && trb_buff_len == 0 - false - it does not matter in this >case >> trb_buff_len == td_total_len - true > >Why trb_buff_len equals to td_total_length? Considering the bulk transfer >with request length larger than 64KB. > You have right, there might still be a problem with ZLP. I've posted the v3 implemented a little differently. Thanks Pawel > >> so whole condition is true. >> >> Because more_trb_comming = true so: >> if (more_trbs_coming) >> return 1; >> returns TD_SIZE = 1 >> >> For TRB2 - ZLP: >> more_trbs_coming = false >> transferred == 0 && trb_buff_len == 0 - false - it does not matter in this >case >> trb_buff_len == td_total_len - true >> >> Because more_trb_comming = false so function returns TD_SIZE = 0 for >last ZLP trb. >> >> Pawel