All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mauro Carvalho Chehab <mchehab@redhat.com>
To: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Devin Heitmueller <dheitmueller@kernellabs.com>,
	linux-media@vger.kernel.org, srinivasa.deevi@conexant.com,
	Maxime Ripard <maxime.ripard@free-electrons.com>
Subject: Re: cx231xx: DMA problem on ARM
Date: Mon, 26 Sep 2011 14:32:47 -0300	[thread overview]
Message-ID: <4E80B73F.5020804@redhat.com> (raw)
In-Reply-To: <20110926101323.41708d64@skate>

Em 26-09-2011 05:13, Thomas Petazzoni escreveu:
> Hello Mauro,
> 
> Le Fri, 23 Sep 2011 23:15:54 -0300,
> Mauro Carvalho Chehab <mchehab@redhat.com> a écrit :
> 
>>> And still the result is the same: we get a first frame, and then
>>> nothing more, and we have a large number of error messages in the
>>> kernel logs.
>>
>> I don't think that this is related to the power manager anymore. It can
>> be related to cache coherency and/or to iommu support.
> 
> As you suspected, increasing PWR_SLEEP_INTERVAL didn't change anything.
> What do you suggest to track down the potential cache coherency issues ?

Take a look at the ML. The SoC people discussed a lot about cache
coherency problems and how to solve it. Videobuf2 has a better support
on embedded world. I would take a look on it and see what it does different
than other drivers. Maybe Jonathan Corbet patches for the ccic driver may
help you.

It is probably a good idea to change cx231xx to use videobuf2, in order to
fix this issue.

Thanks,
Mauro
> 
> Best regards,
> 
> Thomas


  reply	other threads:[~2011-09-26 17:32 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-21 11:56 cx231xx: DMA problem on ARM Thomas Petazzoni
2011-09-21 12:04 ` Devin Heitmueller
2011-09-21 19:17   ` Thomas Petazzoni
2011-09-22 14:45   ` Thomas Petazzoni
2011-09-22 15:09     ` Devin Heitmueller
2011-09-22 15:29       ` Thomas Petazzoni
2011-09-23 12:04         ` Thomas Petazzoni
2011-09-23 12:26           ` Sri Deevi
2011-09-24 18:04             ` Thomas Petazzoni
2011-09-24  2:15           ` Mauro Carvalho Chehab
2011-09-26  8:13             ` Thomas Petazzoni
2011-09-26 17:32               ` Mauro Carvalho Chehab [this message]
2011-09-26 19:02                 ` Laurent Pinchart
2011-09-26 19:59                   ` Thomas Petazzoni
2011-09-26 20:03                     ` Mauro Carvalho Chehab

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=4E80B73F.5020804@redhat.com \
    --to=mchehab@redhat.com \
    --cc=dheitmueller@kernellabs.com \
    --cc=linux-media@vger.kernel.org \
    --cc=maxime.ripard@free-electrons.com \
    --cc=srinivasa.deevi@conexant.com \
    --cc=thomas.petazzoni@free-electrons.com \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.