From: Vinod Koul <vinod.koul@intel.com>
To: Takashi Iwai <tiwai@suse.de>
Cc: alsa-devel@alsa-project.org
Subject: Re: [PATCH] ALSA: hda: Abort capability probe at invalid register read
Date: Wed, 18 Oct 2017 15:59:44 +0530 [thread overview]
Message-ID: <20171018102944.GY30097@localhost> (raw)
In-Reply-To: <s5hfuahxb9n.wl-tiwai@suse.de>
On Wed, Oct 18, 2017 at 07:42:12AM +0200, Takashi Iwai wrote:
> On Wed, 18 Oct 2017 05:24:16 +0200,
> Vinod Koul wrote:
> >
> > On Tue, Oct 17, 2017 at 07:15:08PM +0200, Takashi Iwai wrote:
> > > On Tue, 17 Oct 2017 19:15:08 +0200,
> > > Vinod Koul wrote:
> > > >
> > > > On Tue, Oct 17, 2017 at 04:47:11PM +0200, Takashi Iwai wrote:
> > > > > The loop in snd_hdac_bus_parse_capabilities() may go to nirvana when
> > > > > it hits an invalid register value read:
> > > > >
> > > > > BUG: unable to handle kernel paging request at ffffad5dc41f3fff
> > > > > IP: pci_azx_readl+0x5/0x10 [snd_hda_intel]
> > > > > Call Trace:
> > > > > snd_hdac_bus_parse_capabilities+0x3c/0x1f0 [snd_hda_core]
> > > > > azx_probe_continue+0x7d5/0x940 [snd_hda_intel]
> > > > > .....
> > > > >
> > > > > This happened on a new Intel machine, and we need to check the value
> > > > > and abort the loop accordingly.
> > > >
> > > > okay and what machine is the problem here. I have had a similar bug report
> > > > from Gfx CI guys on CFL machine. Turns out the BIOS was buggy and we fixed
> > > > that up by upgrading the BIOS.
> > >
> > > Yes, it's a CFL-H. Possibly a buggy BIOS, but the driver still
> > > shouldn't crash.
> >
> > Okay so can you ask them to update BIOS and check.
> >
> > > > Yes it is a good idea to keep this guard but -1 would mean that HW read is
> > > > failing which points to some other issue here
> > >
> > > Right.
> >
> > In this case should we send this to stable? I have not seen this crashing
> > till now except bad BIOS issue
>
> People will be getting test hardware now and see the Oops.
> We can't guarantee the sane BIOS, and obviously the current code does
> crash easily, and yet the code fix is trivial -- a perfect situation
> for stable :)
Right :), But do make sure to ask for BIOS update on that board.
Acked-By: Vinod Koul <vinod.koul@intel.com>
--
~Vinod
prev parent reply other threads:[~2017-10-18 10:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-17 14:47 [PATCH] ALSA: hda: Abort capability probe at invalid register read Takashi Iwai
2017-10-17 15:35 ` Ughreja, Rakesh A
2017-10-17 16:16 ` Takashi Iwai
2017-10-18 10:12 ` Ughreja, Rakesh A
2017-10-17 17:15 ` Vinod Koul
2017-10-17 17:15 ` Takashi Iwai
2017-10-18 3:24 ` Vinod Koul
2017-10-18 5:42 ` Takashi Iwai
2017-10-18 10:29 ` Vinod Koul [this message]
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