This is a note to let you know that I've just added the patch titled
usb: musb: host: unmap the buffer for PIO data transfers
to my gregkh-2.6 tree which can be found in directory form at:
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/
and in git form at:
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/patches.git
The filename of this patch is:
usb-musb-host-unmap-the-buffer-for-pio-data-transfers.patch
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
If this patch meets the merge guidelines for a bugfix, it should be
merged into Linus's tree before the next major kernel release.
If not, it will be merged into Linus's tree during the next merge window.
Either way, you will probably be copied on the patch when it gets sent
to Linus for merging so that others can see what is happening in kernel
development.
If you have any questions about this process, please let me know.
>From linux-usb-owner@xxxxxxxxxxxxxxx Tue Oct 5 13:29:25 2010
From: Felipe Balbi <balbi@xxxxxx>
To: Greg KH <greg@xxxxxxxxx>
Cc: Linux USB Mailing List <linux-usb@xxxxxxxxxxxxxxx>,
Maulik Mankad <x0082077@xxxxxx>, Felipe Balbi <balbi@xxxxxx>
Subject: usb: musb: host: unmap the buffer for PIO data transfers
Date: Fri, 24 Sep 2010 13:44:06 +0300
Message-Id: <1285325055-1247-6-git-send-email-balbi@xxxxxx>
From: Maulik Mankad <x0082077@xxxxxx>
The USB stack maps the buffer for DMA if the controller supports DMA.
MUSB controller can perform DMA as well as PIO transfers.
The buffer needs to be unmapped before CPU can perform
PIO data transfers.
Export unmap_urb_for_dma() so that drivers can perform
the DMA unmapping in a sane way.
Signed-off-by: Maulik Mankad <x0082077@xxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/core/hcd.c | 3 ++-
drivers/usb/musb/musb_host.c | 5 +++++
include/linux/usb/hcd.h | 1 +
3 files changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1263,7 +1263,7 @@ static void hcd_free_coherent(struct usb
*dma_handle = 0;
}
-static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
+void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
{
enum dma_data_direction dir;
@@ -1307,6 +1307,7 @@ static void unmap_urb_for_dma(struct usb
URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
}
+EXPORT_SYMBOL_GPL(unmap_urb_for_dma);
static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
gfp_t mem_flags)
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -41,6 +41,7 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/list.h>
+#include <linux/dma-mapping.h>
#include "musb_core.h"
#include "musb_host.h"
@@ -1332,6 +1333,8 @@ void musb_host_tx(struct musb *musb, u8
*/
if (length > qh->maxpacket)
length = qh->maxpacket;
+ /* Unmap the buffer so that CPU can use it */
+ unmap_urb_for_dma(musb_to_hcd(musb), urb);
musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
qh->segsize = length;
@@ -1752,6 +1755,8 @@ void musb_host_rx(struct musb *musb, u8
#endif /* Mentor DMA */
if (!dma) {
+ /* Unmap the buffer so that CPU can use it */
+ unmap_urb_for_dma(musb_to_hcd(musb), urb);
done = musb_host_packet_rx(musb, urb,
epnum, iso_err);
DBG(6, "read %spacket\n", done ? "last " : "");
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -329,6 +329,7 @@ extern int usb_hcd_submit_urb(struct urb
extern int usb_hcd_unlink_urb(struct urb *urb, int status);
extern void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb,
int status);
+extern void unmap_urb_for_dma(struct usb_hcd *, struct urb *);
extern void usb_hcd_flush_endpoint(struct usb_device *udev,
struct usb_host_endpoint *ep);
extern void usb_hcd_disable_endpoint(struct usb_device *udev,
--
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