On Thu, Aug 12, 2010 at 12:22:54AM +0530, DebBarma, Tarun Kanti wrote: > True; however if we go by that argument than we can also assume pdata > is valid, so that we would not need the below check. If pdev was ever NULL in a probe function, the kernel deserves to OOPS so that you have a backtrace to fix the bugger. Basically, a probe function is only called when the driver finds a matching device to bind to - so the device _must_ already exist and be valid. It's basically guaranteed. So checking for a NULL pdev is not only a waste of space, it's a waste of CPU time and developer time writing the check as well. On the other hand, platform data passed in via a platform device _is_ liable to be NULL if whatever created the platform device didn't set the platform data up. So we can't guarantee that the platform data will exist. So a NULL check is appropriate here. So, if an API in normal operation requires non-NULL data to be passed, don't bother checking for a NULL pointer. If you're passed a NULL pointer in this situation, you deserve to OOPS so you get a backtrace to fix the problem rather than silently ignoring the problem. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
