Re: [PATCH] arch/powerpc/lib/copy_32.S: Use alternate memcpy for MPC512x and MPC52xx
From: Segher Boessenkool <hidden>
Date: 2010-07-09 12:58:27
From: Segher Boessenkool <hidden>
Date: 2010-07-09 12:58:27
quoted
quoted
Actually, this is something which might need closer attention - and maybe some support in the device tree indicating which read or write width a device can accept?There already is "device-width"; the drivers never should use any other access width unless they *know* that will work.Wouldn't you want to use "bank-width" instead?
We were talking about single devices. But, sure, when you have multiple devices in parallel the driver needs to know about that.
It would be nice to have a device tree property that can specify that all access widths supported by the CPU will work, though.
Oh please no. A device binding should not depend on what CPU there is in the system. There could be multiple CPUs of different architectures, even. To figure out how to access a device, the driver looks at the device's node, and all its parent nodes (or asks generic code to do that, or platform code). Segher