On Thu, 15 May 2014, Mark Brown wrote:
On Thu, May 15, 2014 at 04:17:44PM +0100, Liviu Dudau wrote:
On Thu, May 15, 2014 at 03:11:48PM +0100, Alan Stern wrote:
On Wed, 14 May 2014, Mark Brown wrote:
Did you folks tested this for all sorts of host controllers? I have no way to verify that it works, and last I heard, many (or even most) controllers don't work right with 64-bit DMA.
I have tested it with a host controller that is capable of 64-bit DMA and without this change it doesn't work. At the moment it is the only known USB host controller enabled for arm64. And 64-bit DMA works fine on arm64.
We should probably conditionalise the device configuration on dma_set_mask() succeeding - any device that can't handle 64 bit DMA should be set up to constrain things appropriately.
Last I heard, there were EHCI controllers that claimed to handle 64-bit DMA but got it wrong. I don't know to what extent this may still be true.
Alan Stern