All of lore.kernel.org
 help / color / mirror / Atom feed
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "Michel Dänzer" <michel@daenzer.net>
Cc: xorg-driver-ati@lists.x.org,
	Cedric Cano <ccano@interfaceconcept.com>,
	dri-devel@lists.freedesktop.org
Subject: Re: [PATCH 3/6] drm/radeon: Writeback endian fixes
Date: Fri, 15 Jul 2011 01:34:49 +1000	[thread overview]
Message-ID: <1310657689.4968.279.camel@pasglop> (raw)
In-Reply-To: <1310656765.22333.10.camel@thor.local>

On Thu, 2011-07-14 at 17:19 +0200, Michel Dänzer wrote:
> On Mit, 2011-07-13 at 16:28 +1000, Benjamin Herrenschmidt wrote:
> > The writeback ring pointer and IH ring pointer are read using le32_to_cpu
> > so we do not want the chip to byteswap them on big-endian.
> > 
> > We still want to byteswap the ring itself and the IBs, so we don't touch
> > that but we remove setting of the byteswap bits in CP_RB_RPTR_ADDR and
> > IH_CNTL.
> > 
> > In general, for things like that where we control all the accessors easily,
> > we are better off doing the swap in SW rather than HW. Paradoxally, it does
> > keep the code closer to x86 and avoid using poorly tested HW features.
> 
> Absolutely. Unfortunately, when I fixed the CP writeback code to use
> le32_to_cpu(), I didn't realize the code for some GPU families was
> already using HW swappers for this. 
> 
> 
> > I also changed the use of RADEON_ to R600_ in a couple of cases to be more
> > consistent with the surrounding code.
> 
> That should probably be in a separate patch. Either way, though:

I thought about it and decided it was trivial enough not to bother
re-doing the patches.

Alex/Dave/whoever's in charge, feel free to apply the current batch,
I'll send further cleanups/fixes as separate patches, possibly not
before next week or so.

Cheers,
Ben.

> Reviewed-by: Michel Dänzer <michel@daenzer.net>



_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel

      reply	other threads:[~2011-07-14 15:34 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-13  6:28 [PATCH 3/6] drm/radeon: Writeback endian fixes Benjamin Herrenschmidt
2011-07-13 14:42 ` Alex Deucher
     [not found]   ` <CADnq5_M2v5CdVNxGqsTfKYT37=p2A5dQ3zcP9NkH42rOVBHDEQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-07-13 21:41     ` Benjamin Herrenschmidt
2011-07-14  2:24       ` Alex Deucher
2011-07-14 15:19 ` Michel Dänzer
2011-07-14 15:34   ` Benjamin Herrenschmidt [this message]

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=1310657689.4968.279.camel@pasglop \
    --to=benh@kernel.crashing.org \
    --cc=ccano@interfaceconcept.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=michel@daenzer.net \
    --cc=xorg-driver-ati@lists.x.org \
    /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.