From ff9c895f07d36193c75533bda8193bde8ca99d02 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 2 Apr 2010 13:27:28 -0400 Subject: USB: fix usbmon and DMA mapping for scatter-gather URBs This patch (as1368) fixes a rather obscure bug in usbmon: When tracing URBs sent by the scatter-gather library, it accesses the data buffers while they are still mapped for DMA. The solution is to move the mapping and unmapping out of the s-g library and into the usual place in hcd.c. This requires the addition of new URB flag bits to describe the kind of mapping needed, since we have to call dma_map_sg() if the HCD supports native scatter-gather operation and dma_map_page() if it doesn't. The nice thing about having the new flags is that they simplify the testing for unmapping. The patch removes the only caller of usb_buffer_[un]map_sg(), so those functions are #if'ed out. A later patch will remove them entirely. As a result of this change, urb->sg will be set in situations where it wasn't set previously. Hence the xhci and whci drivers are adjusted to test urb->num_sgs instead, which retains its original meaning and is nonzero only when the HCD has to handle a scatterlist. Finally, even when a submission error occurs we don't want to hand URBs to usbmon before they are unmapped. The submission path is rearranged so that map_urb_for_dma() is called only for non-root-hub URBs and unmap_urb_for_dma() is called immediately after a submission error. This simplifies the error handling. Signed-off-by: Alan Stern CC: Signed-off-by: Greg Kroah-Hartman --- include/linux/usb.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include') diff --git a/include/linux/usb.h b/include/linux/usb.h index 739f1fd1cc15..99833029e5a8 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -965,10 +965,19 @@ extern int usb_disabled(void); * needed */ #define URB_FREE_BUFFER 0x0100 /* Free transfer buffer with the URB */ +/* The following flags are used internally by usbcore and HCDs */ #define URB_DIR_IN 0x0200 /* Transfer from device to host */ #define URB_DIR_OUT 0 #define URB_DIR_MASK URB_DIR_IN +#define URB_DMA_MAP_SINGLE 0x00010000 /* Non-scatter-gather mapping */ +#define URB_DMA_MAP_PAGE 0x00020000 /* HCD-unsupported S-G */ +#define URB_DMA_MAP_SG 0x00040000 /* HCD-supported S-G */ +#define URB_MAP_LOCAL 0x00080000 /* HCD-local-memory mapping */ +#define URB_SETUP_MAP_SINGLE 0x00100000 /* Setup packet DMA mapped */ +#define URB_SETUP_MAP_LOCAL 0x00200000 /* HCD-local setup packet */ +#define URB_DMA_SG_COMBINED 0x00400000 /* S-G entries were combined */ + struct usb_iso_packet_descriptor { unsigned int offset; unsigned int length; /* expected length */ -- cgit v1.2.3