On Fri, Jan 04, 2019 at 09:24:14AM +0000, Ye Li wrote: > When running usb dwc3 gadget driver, we meet random USB enumeration failure > in fastboot. > The root cause is a cache coherence issue. When it happens, the ctrl_req in > gadget driver is allocated at 0xfe932f40, and the usb_composite_dev (cdev) > is allocated at 0xfe932f60. So after we submit the setup request (cache > flushed) to USB > controller, any accessing to usb_composite_dev variable will cause the cache > line refill, then > when setup transfer is completed, reading the setup data in ctrl_req will > gets old value from > cache not from memory. > > The ctrl_req is allocated by API dma_alloc_coherent, but u-boot don't have > cohernet memory. > so it still needs cache maintain operations before/after HW accessing. Since > the cache flush or > invalidate bases on cache line, so when the allocated memory size is not > cache line aligned, > potentially it may meet such issue. > > This patch modifies the dma_alloc_coherent API to round the size to cache > line aligned. > > Signed-off-by: Ye Li <ye...@nxp.com> > Reviewed-by: Peng Fan <peng....@nxp.com>
Applied to u-boot/master, thanks! -- Tom
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