Re: Bug/Regression - Ralink RT2800 kernel deference issue since kernel 5.14

[Stanislaw Gruszka <stf_xl@wp.pl>]

On Sun, Nov 21, 2021 at 02:38:02PM +0100, Thorsten Leemhuis wrote:
> Hi, this is your Linux kernel regression tracker speaking.
> 
> CCing regression mailing list, which should be in the loop for all
> regressions, as explained here:
> https://www.kernel.org/doc/html/latest/admin-guide/reporting-issues.html
> 
> Also adding Helmut and Stanislaw (or just a different of his
> addresses?), as afaics nothing happened since the report.

FYI: stf_xl@wp.pl is the only valid public e-mail address currently
used by me.

> On 12.11.21 22:21, Robert W wrote:
> > 
> > I have recently tried to upgrade a system to run the 5.14 kernel and
> > noticed that I was getting hangs on the system which seem to relate to
> > this wireless dongle which I am running hostapd against to provide a
> > small AP. Since that time kernel 5.15 was released and I have tested
> > that kernel as well and the problem persists.  The issue sometimes
> > occurs within an hour and other times it takes a few hours. I have tried
> > to narrow down what is causing the issue.  I thought it might be a
> > change elsewhere outside the mac80211/driver area so I tried to run the
> > wireless backports 5.15-rc6 on top of the last stable kernel of 5.13 so
> > as to have the smallest number of changes on the system. The backports
> > crashes with the same error.  I have included below the netconsole
> > output and the gdb of the kernel module in question. The capture was
> > from when I was using the backports, but the error  is the same.  I hope
> > the pastebins are okay to use on the list.  I did try to get some
> > assistance on linux-wireless IRC and some one asked for the outputs I
> > had for the information so I am reusing them here.
> > 
> > The following pastebin is the data sent to a netconsole instance.
> > 
> > https://pastebin.com/UxRrTtUh
<snip>
> > (gdb) list *(rt2x00queue_create_tx_descriptor+0x176)
> > 0x37e6 is in rt2x00queue_create_tx_descriptor (/home/robert/backport/backports-5.15-rc6-1/drivers/net/wireless/ralink/rt2x00/rt2x00queue.c:324).
> > 319                      */
> > 320                     if (sta && txdesc->u.ht.mcs > 7 &&
> > 321                         sta->smps_mode == IEEE80211_SMPS_DYNAMIC)
> > 322                             __set_bit(ENTRY_TXD_HT_MIMO_PS, &txdesc->flags);
> > 323             } else {
> > 324                     txdesc->u.ht.mcs = rt2x00_get_rate_mcs(hwrate->mcs);
> > 325                     if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
> > 326                             txdesc->u.ht.mcs |= 0x08;
> > 327             }
> > 328

Looking at the mailing list archives, seems Felix already provided
patch for this. Hopefully patch fixes the problem. However if changes
in the rt2x00 drivers are needed further, I can look at this.

Regards
Stanislaw