[alsa-devel] [BUG] bdw-rt5650 DSP boot timeout

[Ranjani Sridharan]

On Tue, 2019-07-30 at 10:45 -0700, Jon Flatley wrote:
> On Mon, Jul 29, 2019 at 7:23 PM Pierre-Louis Bossart
> <pierre-louis.bossart at linux.intel.com> wrote:
> > 
> > 
> > 
> > On 7/29/19 7:53 PM, Ranjani Sridharan wrote:
> > > On Mon, 2019-07-29 at 18:02 -0500, Pierre-Louis Bossart wrote:
> > > > 
> > > > On 7/29/19 4:53 PM, Jon Flatley wrote:
> > > > > I've been working on upstreaming the bdw-rt5650 machine
> > > > > driver for
> > > > > the
> > > > > Acer Chromebase 24 (buddy). There seems to be an issue when
> > > > > first
> > > > > setting the hardware controls that appears to be crashing the
> > > > > DSP:
> > > > > 
> > > > > [   51.424554] haswell-pcm-audio haswell-pcm-audio: FW
> > > > > loaded,
> > > > > mailbox
> > > > > readback FW info: type 01, - version: 00.00, build 77, source
> > > > > commit
> > > > > id: 876ac6906f31a43b6772b23c7c983ce9dcb18a19
> > > > > ...
> > > > > [   84.924666] haswell-pcm-audio haswell-pcm-audio: error:
> > > > > audio
> > > > > DSP
> > > > > boot timeout IPCD 0x0 IPCX 0x0
> > > > > [   85.260655] haswell-pcm-audio haswell-pcm-audio: ipc: --
> > > > > message
> > > > > timeout-- ipcx 0x83000000 isr 0x00000000 ipcd 0x00000000 imrx
> > > > > 0x7fff0000
> > > > > [   85.273609] haswell-pcm-audio haswell-pcm-audio: error:
> > > > > stream
> > > > > commit failed
> > > > > [   85.279746]  System PCM: error: failed to commit stream
> > > > > -110
> > > > > [   85.285388] haswell-pcm-audio haswell-pcm-audio: ASoC:
> > > > > haswell-pcm-audio hw params failed: -110
> > > > > [   85.293963]  System PCM: ASoC: hw_params FE failed -110
> > > > > 
> > > > > This happens roughly 50% of the time when first setting
> > > > > hardware
> > > > > controls after a reboot. The other 50% of the time the DSP
> > > > > comes up
> > > > > just fine and audio works fine thereafter. Adding "#define
> > > > > DEBUG 1"
> > > > > to
> > > > > sound/soc/intel/haswell/sst-haswell-ipc.c makes the issue
> > > > > occur
> > > > > much
> > > > > less frequently in my testing. Seems like a subtle timing
> > > > > issue.
> > > > > 
> > > > > There were timing issues encountered during the bringup of
> > > > > the 2015
> > > > > chromebook pixel (samus) which uses the bdw-rt5677 machine
> > > > > driver.
> > > > > Those were slightly different, and manifested during repeated
> > > > > arecords. Both devices use the same revision of the sst2
> > > > > firmware.
> > > > > 
> > > > > Any ideas for how to debug this?
> > > > 
> > > > this could be trying to send an IPC while you are already
> > > > waiting
> > > > for
> > > > one to complete. we've seen this before with SOF, if the IPCs
> > > > are
> > > > not
> > > > strictly serialized then things go in the weeds and timeout.
> > > 
> > > Pierre/Jon
> > > 
> > > In this case it looks like the DSP boot failed leading to the IPC
> > > timeout? WOndering if increasing the boot timeout would help?
> 
> I did actually try this without success.
> 
> > 
> > Yes, that too. The boot timeout is typically experimentally
> > defined, and
> > never decreasing due to platform variations...
> > I am still leaning more on the side of an side effect between two
> > IPCs,
> > the added DEBUG points to the printk which solves timing issues.
> > The
> > boot timeout would typically not be impacted by such changes.
> 
> I think the real struggle I'm having is finding a good debugging
> method that doesn't impact the timing of the IPCs significantly (as
> adding DEBUG seems to). This could maybe be overcome with using a
> stress test to reproduce. The crash only seems to occur when first
> booting the DSP, and so far I've been testing this by completely
> power
> cycling the machine on every test, which is very slow and tedious. So
> maybe the issue with DEBUG defined occurs 1 in 20 reboots rather than
> 1 in 2, I wouldn't know. If there's a way to reboot the DSP and
> reproduce this crash without rebooting the entire device that would
> be
> very helpful to me.
Maybe you've already tried this. But, how about blacklisting the audio
driver and then trying a modprobe/rmmod to insert and remove themodule. This should attempt to boot the DSP upon every modprobe. 
But what I am not sure about is whether the rmmod would succeed if the
IPC times out because the DSP has crashed.

Thanks,
Ranjani
> 
> Thanks,
> Jon