Em Wed, 29 Mar 2017 11:57:22 +0200 Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> escreveu: > On Tue, Mar 28, 2017 at 06:48:02AM -0300, Mauro Carvalho Chehab wrote: > > Em Fri, 17 Mar 2017 10:24:15 +0900 > > Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> escreveu: > > > > > On Thu, Mar 16, 2017 at 09:08:40PM -0300, Mauro Carvalho Chehab wrote: > > > > The dwc2 hardware doesn't like to do DMA transfers without > > > > aligning data in DWORD. The driver also assumes that, even > > > > when there's no DMA, at dwc2_read_packet(). > > > > > > > > That cause buffer overflows, preventing some drivers to work. > > > > > > Why aren't the drivers being fixed? This is a well-known (hopefully) > > > restriction on USB data buffers, can't the uvc_driver be fixed? > > > > I talked to Laurent about on IRC. He told that he is willing to consider > > that option, if the USB API explicitly states that all buffers must be > > dword-aligned (and/or buffer sizes). > > > > IMHO, he has a point: if this is a restriction of for usb transfer > > buffers, it should be documented somewhere. > > > > Yet, a quick check with: > > $ git grep -i dword Documentation/usb/ > > $ git grep -i align Documentation/usb/ > > > > Didn't hit anything related to it. > > Hm, most of the USB documentation is in the kerneldoc in the USB code > itself, and is built that way. I'm pretty sure this is documented > somewhere, but I can't seem to find it at the moment either :( > > Care to write a patch for that? :) Sure. Btw, I noticed that not all USB documents were converted yet to ReST, so I took the time to convert the core documents to ReST too. I kept the driver-specific documentation at Documentation/usb. The final result is at: http://www.infradead.org/~mchehab/kernel_docs/driver-api/usb/index.html I'll be sending the documentation patches in a few. Thanks, Mauro
