Alan Stern wrote: > On Mon, 9 Mar 2009, David Vrabel wrote: > >> The g_file_storage module part fills an IN buffer if the requested read >> would have ended in the middle of a page. With wireless USB this can >> result in enqueued requests that are not a multiple of wMaxPacketSize >> (e.g., 3584) and consequentially the host would receive an unexpected >> short packet. >> >> Is there are reason for this check for the page boundary? Is it simply >> an optimization so subsequent calls to vfs_read() are page-aligned? > > That's right. > >> The attached patch simply removes the check for partial pages. > > Can you rewrite it so that the check is removed only when > wMaxPacketSize > 512? I'll make it so it aligns on a page boundary iff it results in buffers that are a multiple of wMaxPacketSize. This will be useful if wMaxPacketSize is 1k or 2k. David -- David Vrabel, Senior Software Engineer, Drivers CSR, Churchill House, Cambridge Business Park, Tel: +44 (0)1223 692562 Cowley Road, Cambridge, CB4 0WZ http://www.csr.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
