On Wed, Aug 01, 2012 at 11:53:36AM +0800, Shawn Guo wrote:

On Wed, Aug 01, 2012 at 04:31:04AM +0200, Marek Vasut wrote:

quoted

quoted

Couple of reasons for asking: No other SPI master driver calls it in the
remove function (unless I missed it), most drivers don't call it in the
probe function error path, and if I call it in the remove function in a
SPI master driver I am working on, and load/unload the module several
times in a row, I get a nasty kernel crash.

It seems the spi_master class takes care of that kfree() in 
spi.c:spi_master_release() . Good catch, thanks!

I do not hardware setup to confirm that right away.  When
spi_master_release will be called exactly?  The time that
spi_master_put gets called?  I'm trying to understand if the kfree
is not needed only in remove function, or both probe and remove.

I think the call to spi_master_put() triggers the call to spi_master_release().
If so, kfree() would not be needed at all, and the documentation is wrong.

Thanks,
Guenter