* Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers
@ 2021-12-04 14:15 Hans de Goede
2021-12-05 6:46 ` Thorsten Leemhuis
2021-12-05 8:20 ` Greg Kroah-Hartman
0 siblings, 2 replies; 6+ messages in thread
From: Hans de Goede @ 2021-12-04 14:15 UTC (permalink / raw)
To: Mathias Nyman, Pavankumar Kondeti, Greg Kroah-Hartman; +Cc: linux-usb
Hi All,
There are several bug reports (arch and Fedora) about USB problems
starting with kernel 5.14.14 (5.14.13 is ok):
https://bugzilla.redhat.com/show_bug.cgi?id=2019788
https://bbs.archlinux.org/viewtopic.php?pid=2006862
And 5.16.6, which has the hub address0_mutex fixes does not
fix these problems for some users.
Looking at the history between those 2 commit ff0e50d3564f
("xhci: Fix command ring pointer corruption while aborting a command"):
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ff0e50d3564f
stood out to me as a possible cause of this. So I've build
a test 5.15.6 kernel for Fedora users with that commit reverted
and 2 users have now reported that this fixes things for them
(see https://bugzilla.redhat.com/show_bug.cgi?id=2019788).
The reason why this stood out to me is because doing a 32 bit
write over a possibly 64 bit databus to the xHCI controller may
result in the hw doing a 64 bit read + modify 32 bit + 64 bit write,
so I think that the following is happening after the commit:
sw: read 32 bit
hw: read 64 bit, return 32 bit
sw: modify it
sw: write 32 bit
hw: read 64 bit
hw: modify 32 bit of 64 bit wor5d
hw: write 64 bit
Which actually makes the chances of hitting the problem the commit
tries to fix larger on controllers using a 64 bit data bus.
Note this is just a theory, but it seems plausible to me.
All problem reports are people using integrated Intel xHCI controllers
which I believe are likely to use a 64 bit data-bus.
Regards,
Hans
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers
2021-12-04 14:15 Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers Hans de Goede
@ 2021-12-05 6:46 ` Thorsten Leemhuis
2021-12-05 8:20 ` Greg Kroah-Hartman
2021-12-05 8:20 ` Greg Kroah-Hartman
1 sibling, 1 reply; 6+ messages in thread
From: Thorsten Leemhuis @ 2021-12-05 6:46 UTC (permalink / raw)
To: Hans de Goede, Mathias Nyman, Pavankumar Kondeti, Greg Kroah-Hartman
Cc: linux-usb
Hi, this is your Linux kernel regression tracker speaking.
On 04.12.21 15:15, Hans de Goede wrote:
> Hi All,
>
> There are several bug reports (arch and Fedora) about USB problems
> starting with kernel 5.14.14 (5.14.13 is ok):
>
> https://bugzilla.redhat.com/show_bug.cgi?id=2019788
> https://bbs.archlinux.org/viewtopic.php?pid=2006862
>
> And 5.16.6, which has the hub address0_mutex fixes does not
> fix these problems for some users.
>
> Looking at the history between those 2 commit ff0e50d3564f
> ("xhci: Fix command ring pointer corruption while aborting a command"):
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ff0e50d3564f
>
> stood out to me as a possible cause of this. So I've build
> a test 5.15.6 kernel for Fedora users with that commit reverted
> and 2 users have now reported that this fixes things for them
> (see https://bugzilla.redhat.com/show_bug.cgi?id=2019788).
>
> The reason why this stood out to me is because doing a 32 bit
> write over a possibly 64 bit databus to the xHCI controller may
> result in the hw doing a 64 bit read + modify 32 bit + 64 bit write,
> so I think that the following is happening after the commit:
>
> sw: read 32 bit
> hw: read 64 bit, return 32 bit
> sw: modify it
> sw: write 32 bit
> hw: read 64 bit
> hw: modify 32 bit of 64 bit wor5d
> hw: write 64 bit
>
> Which actually makes the chances of hitting the problem the commit
> tries to fix larger on controllers using a 64 bit data bus.
>
> Note this is just a theory, but it seems plausible to me.
>
> All problem reports are people using integrated Intel xHCI controllers
> which I believe are likely to use a 64 bit data-bus.
FWIW, the commit is known to cause problems, one of them is found here:
https://lore.kernel.org/lkml/35f7428b39f996c793f5b4a6a314772681c73d7a.camel@apache.org/
This commit should improve the situation (and afaics hopefully fix all
problems related to it):
https://lore.kernel.org/stable/20211126122340.1193239-2-mathias.nyman@linux.intel.com/
Greg wants to sent it upstream today:
https://lore.kernel.org/lkml/YatGfEzzniH%2FSrn4@kroah.com/
Guess he soon after will backport it to the stable trees as well.
HTH, Ciao, Thorsten
#regzbot ^backmonitor
https://lore.kernel.org/lkml/35f7428b39f996c793f5b4a6a314772681c73d7a.camel@apache.org/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers
2021-12-05 6:46 ` Thorsten Leemhuis
@ 2021-12-05 8:20 ` Greg Kroah-Hartman
0 siblings, 0 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2021-12-05 8:20 UTC (permalink / raw)
To: Thorsten Leemhuis
Cc: Hans de Goede, Mathias Nyman, Pavankumar Kondeti, linux-usb
On Sun, Dec 05, 2021 at 07:46:39AM +0100, Thorsten Leemhuis wrote:
> Hi, this is your Linux kernel regression tracker speaking.
>
> On 04.12.21 15:15, Hans de Goede wrote:
> > Hi All,
> >
> > There are several bug reports (arch and Fedora) about USB problems
> > starting with kernel 5.14.14 (5.14.13 is ok):
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=2019788
> > https://bbs.archlinux.org/viewtopic.php?pid=2006862
> >
> > And 5.16.6, which has the hub address0_mutex fixes does not
> > fix these problems for some users.
> >
> > Looking at the history between those 2 commit ff0e50d3564f
> > ("xhci: Fix command ring pointer corruption while aborting a command"):
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ff0e50d3564f
> >
> > stood out to me as a possible cause of this. So I've build
> > a test 5.15.6 kernel for Fedora users with that commit reverted
> > and 2 users have now reported that this fixes things for them
> > (see https://bugzilla.redhat.com/show_bug.cgi?id=2019788).
> >
> > The reason why this stood out to me is because doing a 32 bit
> > write over a possibly 64 bit databus to the xHCI controller may
> > result in the hw doing a 64 bit read + modify 32 bit + 64 bit write,
> > so I think that the following is happening after the commit:
> >
> > sw: read 32 bit
> > hw: read 64 bit, return 32 bit
> > sw: modify it
> > sw: write 32 bit
> > hw: read 64 bit
> > hw: modify 32 bit of 64 bit wor5d
> > hw: write 64 bit
> >
> > Which actually makes the chances of hitting the problem the commit
> > tries to fix larger on controllers using a 64 bit data bus.
> >
> > Note this is just a theory, but it seems plausible to me.
> >
> > All problem reports are people using integrated Intel xHCI controllers
> > which I believe are likely to use a 64 bit data-bus.
>
> FWIW, the commit is known to cause problems, one of them is found here:
>
> https://lore.kernel.org/lkml/35f7428b39f996c793f5b4a6a314772681c73d7a.camel@apache.org/
>
> This commit should improve the situation (and afaics hopefully fix all
> problems related to it):
>
> https://lore.kernel.org/stable/20211126122340.1193239-2-mathias.nyman@linux.intel.com/
>
> Greg wants to sent it upstream today:
>
> https://lore.kernel.org/lkml/YatGfEzzniH%2FSrn4@kroah.com/
>
> Guess he soon after will backport it to the stable trees as well.
>
> HTH, Ciao, Thorsten
>
> #regzbot ^backmonitor
> https://lore.kernel.org/lkml/35f7428b39f996c793f5b4a6a314772681c73d7a.camel@apache.org/
Ah, I should have read the whole thread, yes, this should be the fix for
this.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers
2021-12-04 14:15 Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers Hans de Goede
2021-12-05 6:46 ` Thorsten Leemhuis
@ 2021-12-05 8:20 ` Greg Kroah-Hartman
2021-12-05 12:48 ` Greg Kroah-Hartman
1 sibling, 1 reply; 6+ messages in thread
From: Greg Kroah-Hartman @ 2021-12-05 8:20 UTC (permalink / raw)
To: Hans de Goede; +Cc: Mathias Nyman, Pavankumar Kondeti, linux-usb
On Sat, Dec 04, 2021 at 03:15:15PM +0100, Hans de Goede wrote:
> Hi All,
>
> There are several bug reports (arch and Fedora) about USB problems
> starting with kernel 5.14.14 (5.14.13 is ok):
>
> https://bugzilla.redhat.com/show_bug.cgi?id=2019788
> https://bbs.archlinux.org/viewtopic.php?pid=2006862
>
> And 5.16.6, which has the hub address0_mutex fixes does not
> fix these problems for some users.
>
> Looking at the history between those 2 commit ff0e50d3564f
> ("xhci: Fix command ring pointer corruption while aborting a command"):
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ff0e50d3564f
>
> stood out to me as a possible cause of this. So I've build
> a test 5.15.6 kernel for Fedora users with that commit reverted
> and 2 users have now reported that this fixes things for them
> (see https://bugzilla.redhat.com/show_bug.cgi?id=2019788).
>
> The reason why this stood out to me is because doing a 32 bit
> write over a possibly 64 bit databus to the xHCI controller may
> result in the hw doing a 64 bit read + modify 32 bit + 64 bit write,
> so I think that the following is happening after the commit:
>
> sw: read 32 bit
> hw: read 64 bit, return 32 bit
> sw: modify it
> sw: write 32 bit
> hw: read 64 bit
> hw: modify 32 bit of 64 bit wor5d
> hw: write 64 bit
>
> Which actually makes the chances of hitting the problem the commit
> tries to fix larger on controllers using a 64 bit data bus.
>
> Note this is just a theory, but it seems plausible to me.
>
> All problem reports are people using integrated Intel xHCI controllers
> which I believe are likely to use a 64 bit data-bus.
I think this is fixed by 09f736aa9547 ("xhci: Fix commad ring abort,
write all 64 bits to CRCR register.") in linux-next and I'll be sending
it to Linus in a few hours.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers
2021-12-05 8:20 ` Greg Kroah-Hartman
@ 2021-12-05 12:48 ` Greg Kroah-Hartman
2021-12-07 0:46 ` Tobias Bachmann
0 siblings, 1 reply; 6+ messages in thread
From: Greg Kroah-Hartman @ 2021-12-05 12:48 UTC (permalink / raw)
To: Hans de Goede; +Cc: Mathias Nyman, Pavankumar Kondeti, linux-usb
On Sun, Dec 05, 2021 at 09:20:00AM +0100, Greg Kroah-Hartman wrote:
> On Sat, Dec 04, 2021 at 03:15:15PM +0100, Hans de Goede wrote:
> > Hi All,
> >
> > There are several bug reports (arch and Fedora) about USB problems
> > starting with kernel 5.14.14 (5.14.13 is ok):
> >
> > https://bugzilla.redhat.com/show_bug.cgi?id=2019788
> > https://bbs.archlinux.org/viewtopic.php?pid=2006862
> >
> > And 5.16.6, which has the hub address0_mutex fixes does not
> > fix these problems for some users.
> >
> > Looking at the history between those 2 commit ff0e50d3564f
> > ("xhci: Fix command ring pointer corruption while aborting a command"):
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ff0e50d3564f
> >
> > stood out to me as a possible cause of this. So I've build
> > a test 5.15.6 kernel for Fedora users with that commit reverted
> > and 2 users have now reported that this fixes things for them
> > (see https://bugzilla.redhat.com/show_bug.cgi?id=2019788).
> >
> > The reason why this stood out to me is because doing a 32 bit
> > write over a possibly 64 bit databus to the xHCI controller may
> > result in the hw doing a 64 bit read + modify 32 bit + 64 bit write,
> > so I think that the following is happening after the commit:
> >
> > sw: read 32 bit
> > hw: read 64 bit, return 32 bit
> > sw: modify it
> > sw: write 32 bit
> > hw: read 64 bit
> > hw: modify 32 bit of 64 bit wor5d
> > hw: write 64 bit
> >
> > Which actually makes the chances of hitting the problem the commit
> > tries to fix larger on controllers using a 64 bit data bus.
> >
> > Note this is just a theory, but it seems plausible to me.
> >
> > All problem reports are people using integrated Intel xHCI controllers
> > which I believe are likely to use a 64 bit data-bus.
>
> I think this is fixed by 09f736aa9547 ("xhci: Fix commad ring abort,
> write all 64 bits to CRCR register.") in linux-next and I'll be sending
> it to Linus in a few hours.
Pull request is here:
https://lore.kernel.org/r/Yayq/Xdb/pHSS7/l@kroah.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers
2021-12-05 12:48 ` Greg Kroah-Hartman
@ 2021-12-07 0:46 ` Tobias Bachmann
0 siblings, 0 replies; 6+ messages in thread
From: Tobias Bachmann @ 2021-12-07 0:46 UTC (permalink / raw)
To: Hans de Goede, Greg Kroah-Hartman
Cc: Mathias Nyman, Pavankumar Kondeti, linux-usb
On Sun, Dec 05, 2021, 13:48:18 CET Greg Kroah-Hartman wrote:
> > I think this is fixed by 09f736aa9547 ("xhci: Fix commad ring abort,
> > write all 64 bits to CRCR register.") in linux-next and I'll be sending
> > it to Linus in a few hours.
>
> Pull request is here:
> https://lore.kernel.org/r/Yayq/Xdb/pHSS7/l@kroah.com
As one of the affected users, I can confirm that my issue is resolved
in 5.16-rc4, which includes that pull request.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-12-07 0:46 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-12-04 14:15 Regression: "xhci: Fix command ring pointer corruption while aborting a command" breaks USB on Intel controllers Hans de Goede
2021-12-05 6:46 ` Thorsten Leemhuis
2021-12-05 8:20 ` Greg Kroah-Hartman
2021-12-05 8:20 ` Greg Kroah-Hartman
2021-12-05 12:48 ` Greg Kroah-Hartman
2021-12-07 0:46 ` Tobias Bachmann
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