diff options
Diffstat (limited to 'recipes/linux/linux-omap-pm/dvb-fix-dma.diff')
| -rw-r--r-- | recipes/linux/linux-omap-pm/dvb-fix-dma.diff | 60 |
1 files changed, 0 insertions, 60 deletions
diff --git a/recipes/linux/linux-omap-pm/dvb-fix-dma.diff b/recipes/linux/linux-omap-pm/dvb-fix-dma.diff deleted file mode 100644 index e05473fc7f..0000000000 --- a/recipes/linux/linux-omap-pm/dvb-fix-dma.diff +++ /dev/null @@ -1,60 +0,0 @@ -Hi, -I post this patch that fixes a kernel crash that happens when using a dvb -usb stick on a mips platform and I think even on other platforms on which -the dma access in not cache-coherent. - -The problem's origin is that, inside the method usb_bulk_urb_init of file -drivers/media/dvb/dvb-usb/usb-urb.c, stream->urb_list[i]->transfer_buffer -points to a memory area that has been allocated to be dma-coherent but -stream->urb_list[i]->transfer_flags doesn't include the -URB_NO_TRANSFER_DMA_MAP flag and stream->urb_list[i]->transfer_dma is not -set. -When later on the stream->urb_list[i]->transfer_buffer pointer is used -inside function usb_hcd_submit_urb of file drivers/usb/core/hcd.c since the -flag URB_NO_TRANSFER_DMA_MAP is not set the urb->transfer_buffer pointer is -passed to the dma_map_single function that since the address is dma-coherent -returns a wrong tranfer_dma address that later on leads to the kernel crash. - -The problem is solved by setting the URB_NO_TRANSFER_DMA_MAP flag and the -stream->urb_list[i]->transfer_dma address. - -Perhaps to be more safe the URB_NO_TRANSFER_DMA_MAP flag can be set only -if stream->urb_list[i]->transfer_dma != 0. - -I don't know if half of the fault can be of the dma_map_single function that -should anyway returns a valid address both for a not dma-coherent and a -dma-coherent address. - -Just to be clear: -I've done this patch to solve my problem and I tested it only on a mips -platform -but I think it should not cause any problems on other platforms. -I posted it here to help someone else that can have my same problem and to -point it out -to the mantainer of this part of code. -You can use it at your own risk and I'm not resposible in any way for any -problem or -damage that it can cause. -I'm available to discuss about it - -Bye - -Michele Scorcia - --------------------- - - - - ---- /tmp/usb-urb.c 2008-10-08 09:53:23.000000000 +0200 -+++ git/drivers/media/dvb/dvb-usb/usb-urb.c 2008-10-08 09:54:16.000000000 +0200 -@@ -152,7 +152,8 @@ - stream->props.u.bulk.buffersize, - usb_urb_complete, stream); - -- stream->urb_list[i]->transfer_flags = 0; -+ stream->urb_list[i]->transfer_flags = URB_NO_TRANSFER_DMA_MAP; -+ stream->urb_list[i]->transfer_dma = stream->dma_addr[i]; - stream->urbs_initialized++; - } - return 0; |