Re: Driver for rtw8723ds

["Jernej Škrabec" <jernej.skrabec@gmail.com>]

Dne sobota, 13. maj 2023 ob 23:21:47 CEST je Larry Finger napisal(a):
> On 5/13/23 15:13, Jernej Škrabec wrote:
> > Dne sobota, 13. maj 2023 ob 21:55:51 CEST je Larry Finger napisal(a):
> >> On 5/13/23 05:23, Jernej Škrabec wrote:
> >>> Larry,
> >>>
> >>> Dne sreda, 10. maj 2023 ob 23:47:24 CEST je Larry Finger napisal(a):
> >>>> On 5/10/23 16:07, Martin Blumenstingl wrote:
> >>>>> On Wed, May 10, 2023 at 12:02 AM Larry Finger <Larry.Finger@lwfinger.net> wrote:
> >>>>> [...]
> >>>>>> I added that patch to the driver. The user reports that he was able to do a ping
> >>>>>> and an nslookup before it crashed with the following in the log:
> >>>>> That's some positive news alongside the crash log: it seems that a
> >>>>> part of the driver works! :-)
> >>>>>
> >>>>>> [    8.700626] skbuff: skb_over_panic: text:ffff8000011924ac len:3341 put:3341
> >>>>>> head:ffff000003b3c000 data:ffff000003b3c040 tail:0xd4d end:0x2c0 dev:<NULL>
> >>>>> [...]
> >>>>>> Somehow skb->tail was greater than skb->end. Unfortunately I do not have access
> >>>>>> to gdb to tell you what line corresponds to rtw_sdio_rx_skb+0x50 on the MangoPi
> >>>>>> MQ Quad.
> >>>>> I need to have a closer look at the pkg_offset and struct
> >>>>> rtw_rx_pkt_stat which we receive.
> >>>>> Recently my own MangoPI MQ-Quad arrived but I did not have the time to
> >>>>> set it up yet. I'll try to do so during the weekend so I can debug
> >>>>> this on my own.
> >>>>>
> >>>>> Please ping me next week in case I haven't provided any update until then.
> >>>>
> >>>> I have some test prints in to check for skb overrun. My initial indication is
> >>>> that the problem was in the c2h branch of rtw_sdio_rx_skb(), but my next run
> >>>> should verify that. My changes will do a pr_warn_once() when the problem
> >>>> happens, and then drop the skb.
> >>>>
> >>>> My contact reported that he had one run of 3 minutes before the problem
> >>>> happened, which is good news for most of the driver.
> >>>
> >>> I may have discovered something interesting. rtl8723ds vendor driver has
> >>> following checks in RX data parsing code:
> >>> https://github.com/lwfinger/rtl8723ds/blob/master/hal/rtl8723d/sdio/rtl8723ds_recv.c#L83-L99
> >>>
> >>> Those checks are absent in rtl8822bs vendor driver, which was my original
> >>> development platform for SDIO. This may indicate some kind of bug in FW
> >>> and/or HW.
> >>>
> >>> I think that at least second check, which checks for exactly the case your
> >>> client experience, can be easily added and tested.
> >>
> >> Thanks for this update. I added the following to the start of rtw_sdio_rx_skb():
> >>          /* fix Hardware RX data error, drop whole recv_buffer */
> >>          if (!(rtwdev->hal.rcr & BIT_ACRC32) && pkt_stat->crc_err) {
> >>                  kfree_skb(skb);
> >>                  return;
> >>          }
> >> I think that duplicates the code in the vendor driver.
> >>
> >> I have not heard from my user as to whether it helps. My communications with him
> >> are at https://github.com/lwfinger/rtl8723ds/issues/37.
> > 
> > I had second part in mind (see attachment), but this is IMO only sanity check
> > and it will mask the issue. At this point I'm not sure if this is something that
> > can happen occasionally or is there additional bug in rtw88 code. I'll check
> > rtl8723ds c2h code in greater detail.
> > 
> > In any case, I would argue that all 3 patches in this thread are valid and
> > should be submitted upstream.
> 
> That patch looks good. I ill apply it to my rtw88 repo.

I see that issue is still there. Next idea would be to check if RX aggregation
is the problem. Just commenting out call to rtw_sdio_enable_rx_aggregation()
is enough to disable it.

Best regards,
Jernej