Messages in this thread | | | Date | Wed, 11 Jun 2008 10:39:01 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [S] Re: [linux-uwb] packet size problem |
| |
On Wed, 11 Jun 2008, AntonioLin wrote:
> Hi All, > > I checked srb->device->request_queue->dma_alignment in usb_stor_bulk_Bulk_transport() routine. , the value is 1023. > > But in usb_stor_bulk_transfer_sglist, the length of first element in sg array is 3584 which is not divisible by 1024. > > > Can you post your /proc/bus/usb/devices ? > > I don't know how to do this, could you descript moe about it ? > (Sorry,I have few experience about Linux.)
All you have to do is:
cat /proc/bus/usb/devices
Or even just tell your email client to include /proc/bus/usb/devices as an attachment. However some Linux distributions don't automatically mount /proc/bus/usb. If yours doesn't, you will have to do (as root):
mount -t usbfs none /proc/bus/usb
before you can access /proc/bus/usb/devices. But in any case it doesn't matter, since you have checked that the value of dma_alignment really is 1023.
Jens, this is a question for you. How come we're getting an SG element whose lenth is 3584 when the request_queue's dma_alignment mask is set to 1023? Is dma_alignment not the right parameter to set?
Alan Stern
| |