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From: Marek Vasut <marex@denx.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] Cache alignment warnings on Tegra (ARM)
Date: Tue, 18 Sep 2012 23:20:30 +0200	[thread overview]
Message-ID: <201209182320.30587.marex@denx.de> (raw)
In-Reply-To: <20120918200443.GA31435@avionic-0098.mockup.avionic-design.de>

Dear Thierry Reding,

> On Tue, Sep 18, 2012 at 09:36:18PM +0200, Marek Vasut wrote:
> > Dear Thierry Reding,
> > 
> > [...]
> > 
> > > > Sure, but after you apply the bounce buffer, you can safely
> > > > invalidate the whole cacheline, so align it up and be done with it.
> > > 
> > > That's what I proposed to do last time around but it was NAK'ed.
> > 
> > By who?
> 
> I think it was Simon Glass and Mike Frysinger. They NAK'ed it for very
> valid reason, so I'm not complaining.
> 
> > > At the
> > > time I didn't ensure that the buffer was actually big enough, which is
> > > why people didn't like it (data on the stack after the DMA buffer might
> > > be invalidated as well).
> > 
> > Correct, thus the bounce buffer.
> 
> I don't think we even need the bounce buffer. All that needs to be done
> is guarantee that the buffers passed to the MMC driver are properly
> aligned and sized.

If you resize the MMC structures and call sizeof() on them to get the size of 
the transfer, the MMC won't work correctly anymore.

> Thierry

Best regards,
Marek Vasut

  parent reply	other threads:[~2012-09-18 21:20 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-12 16:19 [U-Boot] Cache alignment warnings on Tegra (ARM) Tom Warren
2012-09-12 16:49 ` Stephen Warren
2012-09-12 22:38   ` Marek Vasut
2012-09-12 23:10     ` Stephen Warren
2012-09-12 23:42       ` Marek Vasut
2012-09-14 15:53         ` Simon Glass
2012-09-15 20:01           ` Thierry Reding
2012-09-15 20:11             ` Marek Vasut
2012-09-15 20:41               ` Thierry Reding
2012-09-15 20:56                 ` Marek Vasut
2012-09-16  2:45                 ` Simon Glass
2012-09-16  6:49                   ` Thierry Reding
2012-09-17 21:39                     ` Simon Glass
2012-09-18 14:54                       ` Thierry Reding
2012-09-18 18:24                         ` Simon Glass
2012-09-18 18:37                           ` Marek Vasut
2012-09-18 19:00                             ` Thierry Reding
2012-09-18 19:21                               ` Marek Vasut
2012-09-18 19:29                                 ` Thierry Reding
2012-09-18 19:36                                   ` Marek Vasut
2012-09-18 20:04                                     ` Thierry Reding
2012-09-18 20:28                                       ` Simon Glass
2012-09-18 21:21                                         ` Marek Vasut
2012-09-18 22:42                                           ` Simon Glass
2012-09-18 22:44                                             ` Marek Vasut
2012-09-19  5:45                                               ` Thierry Reding
2012-09-18 21:20                                       ` Marek Vasut [this message]
2012-09-19  5:46                                         ` Thierry Reding
2012-09-15 20:19             ` Thierry Reding

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