From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Miguel Ojeda <ojeda@kernel.org>,
Lars Poeschel <poeschel@lemonage.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Geert Uytterhoeven <geert.uytterhoeven@gmail.com>
Subject: Re: parallel panel display stopped working
Date: Fri, 9 Jul 2021 17:54:46 +0300 [thread overview]
Message-ID: <CAHp75VfUHPqccrxe81=jYmiskgWcgTpf3jBjXsPiFpox+Xuyyw@mail.gmail.com> (raw)
In-Reply-To: <CAHp75VfKyqy+vM0XkP9Yb+znGOTVT4zYCRY3A3nQ7C3WNUVN0g@mail.gmail.com>
On Fri, Jul 9, 2021 at 5:40 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> Parallel (4 bits) panel display stopped working.
> I have no time right now to bisect but I have noticed there was quite
> a pile of patches from Lars to the driver recently (yeah, it seems for
> a few months I haven't run my tests against the AUX display driver).
>
> I believe the issue is there somewhere.
>
> Moreover on the removal I have got an oops
>
> [ 218.825445] kernel tried to execute NX-protected page - exploit
> attempt? (uid: 0)
> [ 218.832965] BUG: unable to handle page fault for address: ffff8f8f06559dc0
> [ 218.839863] #PF: supervisor instruction fetch in kernel mode
> [ 218.845540] #PF: error_code(0x0011) - permissions violation
> [ 218.851132] PGD e601067 P4D e601067 PUD e602067 PMD 645a063 PTE
> 8000000006559063
> [ 218.858587] Oops: 0011 [#1] SMP PTI
> [ 218.862099] CPU: 0 PID: 7 Comm: kworker/u4:0 Tainted: G C
> 5.13.0+ #23
> [ 218.869870] Hardware name: Intel Corporation Merrifield/BODEGA BAY,
> BIOS 542 2015.01.21:18.19.48
> [ 218.878681] Workqueue: kacpi_hotplug acpi_device_del_work_fn
> [ 218.884380] RIP: 0010:0xffff8f8f06559dc0
> [ 218.888328] Code: ff ff d2 2b 21 8c ff ff ff ff 08 00 00 00 00 00
> 00 00 78 34 fa 02 8f 8f ff ff 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 <72> 65 67 75 6c 61 74 6f 72 3a 72 65
> 67 75 6c 61 74 6f 72 2e 30 2d
> [ 218.907138] RSP: 0000:ffffad36c0043c90 EFLAGS: 00010246
> [ 218.912387] RAX: ffff8f8f06559dc0 RBX: ffff8f8f062cbc00 RCX: ffff8f8f01239fc8
> [ 218.919542] RDX: 000000002a3cccf8 RSI: 0000000000000001 RDI: ffff8f8f06559480
> [ 218.926701] RBP: ffffffffc037e279 R08: 00000000d5832520 R09: 0000000000000001
> [ 218.933856] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8f8f062cbc00
> [ 218.941010] R13: ffffffffc038e028 R14: ffffffff8c5e0b60 R15: 00000000fffffffd
> [ 218.948166] FS: 0000000000000000(0000) GS:ffff8f8f3e200000(0000)
> knlGS:0000000000000000
> [ 218.956286] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 218.962053] CR2: ffff8f8f06559dc0 CR3: 0000000002ef4000 CR4: 00000000001006f0
> [ 218.969208] Call Trace:
> [ 218.971678] ? hd44780_common_clear_display+0x17/0x30 [hd44780_common]
> [ 218.978252] ? charlcd_write_char+0x21a/0x810 [charlcd]
> [ 218.983519] ? charlcd_puts+0x30/0x60 [charlcd]
> [ 218.988083] ? charlcd_unregister+0x24/0x70 [charlcd]
> [ 218.993167] ? hd44780_remove+0x1e/0x30 [hd44780]
> [ 218.997901] ? platform_remove+0x1f/0x40
> ...
>
> Just for your information and with hope that somebody may test and/or
> reproduce this and fix it. Later on I might find time to bisect the
> other issue I mentioned above.
For time being confirmed the following:
1. a2060f288e15 ("auxdisplay: Call charlcd_backlight in place") has a
remove bug (above), while panel works
2. 66ce7d5c1e12 ("auxdisplay: Use an enum for charlcd backlight on/off
ops") everything works as expected
So, the oops introduced in between those two.
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2021-07-09 14:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-09 14:40 parallel panel display stopped working Andy Shevchenko
2021-07-09 14:54 ` Andy Shevchenko [this message]
2021-07-09 15:45 ` Andy Shevchenko
2021-07-09 16:10 ` Andy Shevchenko
2021-07-14 11:02 ` [RFC] auxdisplay: Fix oops on hd44780 module unloading Lars Poeschel
2021-07-15 14:11 ` Andy Shevchenko
2021-07-15 23:27 ` Miguel Ojeda
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAHp75VfUHPqccrxe81=jYmiskgWcgTpf3jBjXsPiFpox+Xuyyw@mail.gmail.com' \
--to=andy.shevchenko@gmail.com \
--cc=andriy.shevchenko@linux.intel.com \
--cc=geert.uytterhoeven@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=ojeda@kernel.org \
--cc=poeschel@lemonage.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).