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authorAlan Stern <stern@rowland.harvard.edu>2010-04-02 21:27:28 +0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-21 00:21:37 +0400
commitff9c895f07d36193c75533bda8193bde8ca99d02 (patch)
tree386ca8e37734c4810e59a55eaba92e4e88275d14 /include/linux/usb.h
parent0ff8d1b3c858ea7c8daa54f7577971a76d04d283 (diff)
downloadlinux-ff9c895f07d36193c75533bda8193bde8ca99d02.tar.xz
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 <stern@rowland.harvard.edu> CC: <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux/usb.h')
-rw-r--r--include/linux/usb.h9
1 files changed, 9 insertions, 0 deletions
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 */