Re: [PATCH v9] spi: New driver for Altera SPI

On Tue, Feb 15, 2011 at 03:04:49PM +0800, Thomas Chou wrote:

Dear Ryan,

On 02/14/2011 10:20 AM, Ryan Mallon wrote:

quoted

On 02/14/2011 03:10 PM, Thomas Chou wrote:

quoted

This patch adds a new SPI driver to support the Altera SOPC Builder
SPI component. It uses the bitbanging library.

Signed-off-by: Thomas Chou<redacted>
---

quoted

+struct altera_spi {
+	/* bitbang has to be first */
+	struct spi_bitbang bitbang;

Is this still true? I had a quick look and can't see anything which
relies on spi_bitbang being the first entry. Things like this should be
using container_of so that position in the struct is irrelevant.

~Ryan

Yes, sadly true. This is due to the implementation of the bitbanging
library, spi_bitbang.c, which assumes the struct spi_bitbang is the
first of drvdata. Though it could be changed in the future (beyond
this little driver), every bitbanging library user has to follow
this for now.

Should be easy to fix if it is indeed still true (I haven't dug deep
enough to find the design error yet).  Anybody want to volunteer?

g.