tequilaOS/platform_system_core
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Remove urb request size maximum.

Browse source 
The 16kB maximum for transfers was removed from
the kernel in 3.3. Devio has since supported
arbitrary transfer sizes through scatter gather.

See the following kernel patches for context:
"USB: change the memory limits in usbfs URB submission"
"usbdevfs: Use scatter-gather lists for large bulk transfers"

Bug: 67683483
Test: Run usb_async_test app with USB3 : 38MB/s -> 300MB/s
Change-Id: Ia52440cb725561b0f1db1a75aa1b8ab952585826
This commit is contained in:
Jerry Zhang 2018-02-06 18:25:44 -08:00
parent 98aad49d58
commit 3be61d3850
1 changed files with 1 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
libusbhost/usbhost.c
View file

@ -64,10 +64,6 @@
// Some devices fail to send string descriptors if we attempt reading > 255 bytes
#define MAX_STRING_DESCRIPTOR_LENGTH 255
// From drivers/usb/core/devio.c
// I don't know why this isn't in a kernel header
#define MAX_USBFS_BUFFER_SIZE 16384
#define MAX_USBFS_WD_COUNT 10
struct usb_host_context {
@ -664,10 +660,6 @@ int usb_device_bulk_transfer(struct usb_device *device,
{
struct usbdevfs_bulktransfer ctrl;
// need to limit request size to avoid EINVAL
if (length > MAX_USBFS_BUFFER_SIZE)
length = MAX_USBFS_BUFFER_SIZE;
memset(&ctrl, 0, sizeof(ctrl));
ctrl.ep = endpoint;
ctrl.len = length;
@ -727,11 +719,7 @@ int usb_request_queue(struct usb_request *req)
urb->status = -1;
urb->buffer = req->buffer;
// need to limit request size to avoid EINVAL
if (req->buffer_length > MAX_USBFS_BUFFER_SIZE)
urb->buffer_length = MAX_USBFS_BUFFER_SIZE;
else
urb->buffer_length = req->buffer_length;
urb->buffer_length = req->buffer_length;
do {
res = ioctl(req->dev->fd, USBDEVFS_SUBMITURB, urb);