From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH 4/5] musb: use system DMA for unaligned buffers on RTL >= 1.8 Date: Fri, 14 May 2010 14:06:48 +0300 Message-ID: <20100514110648.GA3947@nokia.com> References: <1273664979-493-1-git-send-email-ajay.gupta@ti.com> <1273664979-493-2-git-send-email-ajay.gupta@ti.com> <1273664979-493-3-git-send-email-ajay.gupta@ti.com> <1273664979-493-4-git-send-email-ajay.gupta@ti.com> <20100512175433.GC3285@gandalf> <19F8576C6E063C45BE387C64729E7394044E405169@dbde02.ent.ti.com> Reply-To: felipe.balbi-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <19F8576C6E063C45BE387C64729E7394044E405169-/tLxBxkBPtCIQmiDNMet8wC/G2K4zDHf@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "ext Gupta, Ajay Kumar" Cc: "me-uiRdBs8odbtmTBlB0Cgj/Q@public.gmane.org" , "linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-omap@vger.kernel.org On Thu, May 13, 2010 at 06:13:00AM +0200, ext Gupta, Ajay Kumar wrote: >How about this 'memcpy', this would affect both cpu loading >and performance. That's why using system dma would be a better >approach. but that's not portable. Even if you come up with nice wrappers for system dma usage (which is already ugly, more exported functions) you might end up on a board where system dma has same alignment constraints as mentor dma. Either fall back to pio or use a bounce buffer. That'll work always. Besides, the only offending gadget driver we have is g_ether and that's already 'fixed' by the alignment patch to g_ether. Any other gadget driver causing that, should be fixed too... -- balbi DefectiveByDesign.org -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html