On Wed, Jan 20, 2010 at 11:08:30AM +0100, monstr@xxxxxxxxx wrote: > Hi All, > > I have this patch in my repo. I just added BUG_ON for dma ops. > The reason for that is if driver not setup ops correctly than > the system do bad access to any memory space without any visible reason. > BUG_ON points to it and helps to solve where the problem is. I have a question of principle to raise here. If you have code which does: if (ops->foo) ops->foo(); and ops is NULL, then this code will oops; you will get a full register dump and backtrace. You can use this information along with markup_oops.pl to find out where the problem is. If you add a BUG_ON() to this, the only additional information you end up with is (possibly) a nice friendly message which tells you the file and line number - but you add additional run-time tests to the code. The question is: is this worth it? Is there some problem with the original oops that makes the problem hard to find? Should we be using BUG_ON() to augment normal oopses in this way? -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
