On Tue, Jun 02, 2009 at 09:12:29AM +0200, Jean Delvare wrote: > On Wed, 27 May 2009 13:01:40 +0100, Mark Brown wrote: > > It's extremely common for devices like the CODECs and PMICs used in > > embedded systems to have both I2C and SPI interfaces, selectable via a > Can you please point me at a couple of affected drivers? Most of the Wolfson CODECs in sound/soc/codecs are affected (more than actually have the SPI code at the minute), probably a lot of the other CODECs there too. I'd expect most I2C devices in drivers/mfd will also be affectd. For anything with more than a few registers the tendency is to have both options unless there's a hardware constraint. > I would really expect all I2C-related code to be in one place of the > driver (or even in a separate source file) and same for SPI-related > code. Then surrounding one big block of code with an ifdef doesn't > sound that difficult to read. It's not a legibility issue, it's to do with people remembering to handle all the cases. It's a bit of a PITA but not the end of the world - I'm mentioning this more because you were suggesting that a driver that was still useful with I2C=n was unusual rather than anything else. > driver needs to be reviewed for the CONFIG_I2C=n case. If we add stubs > all around to workaround the link breakage, this means the review never > happens, so the code might as well build and link but not work properly > or at least not be optimal. I wouldn't call this progress. I can't really see a situation where things wouldn't work properly beyond the current situation where I2C support can just be built out - if nobody is running the code then that's a separate issue. > What could be done, OTOH, is to surround all the function declarations > in <linux/i2c.h> with a simple #ifdef CONFIG_I2C, so that mistakes are > caught earlier (build time instead of link time.) That'd be helpful, yes. -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
