Messages in this thread Patch in this message | | | Date | Sat, 1 Oct 2005 16:20:59 -0400 | From | Christopher Li <> | Subject | [PATCH] incrase usbdevfs bulk buffer size |
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Increase the usbdevfs buffer size limit.
I hit this limit with running ehci in the VM. The a single ehci qTD transfer buffer can be 5 pages long, that is 20K. The current devio bulk transfer limit is 16K. I am not sure why the bulk transfer limit is 16K. I can complicate the user space part to work around that, but it seems much simpler just allow usbdevfs to accept bigger buffers.
I did some limited usage test with ehci controller. It seems works for me, it did use a bigger buffer and nothing blow up.
Signed-Off-By: Christopher Li <chrisl@vmware.com>
Index: linux-2.6.13.2/drivers/usb/core/devio.c =================================================================== --- linux-2.6.13.2.orig/drivers/usb/core/devio.c 2005-09-28 13:08:10.000000000 -0700 +++ linux-2.6.13.2/drivers/usb/core/devio.c 2005-10-01 04:58:47.000000000 -0700 @@ -72,7 +72,7 @@ MODULE_PARM_DESC (usbfs_snoop, "true to } while (0) -#define MAX_USBFS_BUFFER_SIZE 16384 +#define MAX_USBFS_BUFFER_SIZE (32*1024) static inline int connected (struct usb_device *dev) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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