From: Wolfgang Wegner <wolfgang@leila.ping.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] convention for SPI dummy data?
Date: Fri, 23 Apr 2010 17:49:10 +0200 [thread overview]
Message-ID: <20100423154910.GQ20047@leila.ping.de> (raw)
In-Reply-To: <201004231134.54565.vapier@gentoo.org>
On Fri, Apr 23, 2010 at 11:34:53AM -0400, Mike Frysinger wrote:
[...]
> > the problem exists in the (coldfire) SPI driver, not in the MMC/SD code.
>
> sorry, i thought you were proposing to fix it in the SPI/MMC driver
no, as far as I can see it is always set to 0xFF there if set explicitly,
i.e. except for the read-only transfers.
> what i've seen so far is that the idle val doesnt matter to most spi devices.
> so on the Blackfin side, we've been defaulting to 0xff so that things do work
> "out of the box" for everyone (at least so far).
Sounds good - however I had just sent a patch implementing CONFIG_SPI_IDLE_VAL.
(I am quite hesitating to simply change such a basic default value because
I fear there might be other devices around relying on current behaviour.
On the other hand, my implementation adds 7 lines of preprocessor stuff,
which also does not look really good.)
Regards,
Wolfgang
next prev parent reply other threads:[~2010-04-23 15:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-23 8:43 [U-Boot] convention for SPI dummy data? Wolfgang Wegner
2010-04-23 15:08 ` Mike Frysinger
2010-04-23 15:18 ` Wolfgang Wegner
2010-04-23 15:34 ` Wolfgang Wegner
2010-04-23 15:34 ` Mike Frysinger
2010-04-23 15:49 ` Wolfgang Wegner [this message]
2010-04-23 15:43 ` [U-Boot] [PATCH RFC] add CONFIG_SPI_IDLE_VAL for cf_spi.c to allow use of spi_mmc Wolfgang Wegner
2011-06-13 18:27 ` Terje B. Nilsen
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