On Mon, Dec 05, 2011 at 06:35:56PM +0100, Ulf Hansson wrote: > Instead of reading a register value everytime we need to > apply a new value for it, maintain a cached copy for it. > This also means we are able to skip writes that are not > needed. I'm not sure this is a good idea. The ARM Primecells require a certain number of bus clocks and MCLK periods between writes to both these registers, and reading them back helps to ensure that we conform to that requirement. Maintaining a cached copy of them allows faster writes to these registers which could cause that requirement to be violated. What you could do is read the register, modify, and check whether the modification has had any effect before writing it back. That will allow unnecessary writes to still be skipped. -- 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
