Hi, Added Marek as USB maintainer.
On 11/17/2016 01:21 PM, Dongwoo Lee wrote: > The transfer request exceeding 4032KB (the maximum number of TRBs per > TD * the maximum size of transfer buffer on TRB) fails on xhci host > with timed out error or babble error state. This failure occurs when > accessing large files on USB mass-storage. Currently with xhci as well > as ehci host, the driver requests maximum 30MB (65536 blks * 512 byte) > to storage at once. However, xhci cannot handle this request because > of the reason mentioned above, even though ehci can handle this. Thus, > transfer request larger than this size should be splitted in order to > limit the length of data in a single TD. > > Even though the single request is splitted into multiple requests, > the transfer speed has affected insignificantly in comparison with > ehci host: 22.6 MB/s on ehci and 22.3 MB/s on xhci for 100MB tranfer. I don't have USB knowledge..So i wonder that this is correct way. Have other guys ever seen the similar issue? > > Reported-by: Jaehoon Chung <[email protected]> > Signed-off-by: Dongwoo Lee <[email protected]> > --- > drivers/usb/host/xhci.c | 30 +++++++++++++++++++++++++++++- > 1 file changed, 29 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c > index 3201177..594026e 100644 > --- a/drivers/usb/host/xhci.c > +++ b/drivers/usb/host/xhci.c > @@ -907,12 +907,40 @@ static int _xhci_submit_int_msg(struct usb_device > *udev, unsigned long pipe, > static int _xhci_submit_bulk_msg(struct usb_device *udev, unsigned long pipe, > void *buffer, int length) > { > + int ret; > + int xfer_max_per_td, xfer_length, buf_pos; > + > if (usb_pipetype(pipe) != PIPE_BULK) { > printf("non-bulk pipe (type=%lu)", usb_pipetype(pipe)); > return -EINVAL; > } > > - return xhci_bulk_tx(udev, pipe, length, buffer); > + /* > + * When transfering data exceeding the maximum number of TRBs per > + * TD (default 64) is requested, the transfer fails with babble > + * error or time out. > + * > + * Thus, huge data transfer should be splitted into multiple TDs. > + */ > + xfer_max_per_td = TRB_MAX_BUFF_SIZE * (TRBS_PER_SEGMENT - 1); xfer_ma_per_td is constant? Then why don't define "XFER_MAX_PER_TD"? Then can remove xfer_max_per_td variable. > + > + buf_pos = 0; can be assigned to 0 when buf_pos is defined? Best Regards, Jaehoon Chung > + do { > + if (length > xfer_max_per_td) > + xfer_length = xfer_max_per_td; > + else > + xfer_length = length; > + > + ret = xhci_bulk_tx(udev, pipe, xfer_length, buffer + buf_pos); > + if (ret < 0) > + return ret; > + > + buf_pos += xfer_length; > + length -= xfer_length; > + > + } while (length > 0); > + > + return ret; > } > > /** > _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
