usb: musb: make use_sg flag URB specific

Since highmem PIO URB handling was introduced in:

8e8a551 usb: musb: host: Handle highmem in PIO mode

when a URB is being handled it may happen that the static use_sg flag
was set by a previous URB with buffer in highmem.  This leads to error
in handling the present URB.

Fix this by making the use_sg flag URB specific.

Cc: stable <stable@vger.kernel.org> # 3.7+
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Fabio Baltieri <fabio.baltieri@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 9 insertions, 10 deletions

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 8914dec49f01..9d3044bdebe5 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -1232,7 +1232,6 @@ void musb_host_tx(struct musb *musb, u8 epnum)
         void __iomem            *mbase = musb->mregs;
         struct dma_channel      *dma;
         bool                    transfer_pending = false;
-        static bool use_sg;
 
         musb_ep_select(mbase, epnum);
         tx_csr = musb_readw(epio, MUSB_TXCSR);
@@ -1463,9 +1462,9 @@ done:
          * NULL.
          */
         if (!urb->transfer_buffer)
-                use_sg = true;
+                qh->use_sg = true;
 
-        if (use_sg) {
+        if (qh->use_sg) {
                 /* sg_miter_start is already done in musb_ep_program */
                 if (!sg_miter_next(&qh->sg_miter)) {
                         dev_err(musb->controller, "error: sg list empty\n");
@@ -1484,9 +1483,9 @@ done:
 
         qh->segsize = length;
 
-        if (use_sg) {
+        if (qh->use_sg) {
                 if (offset + length >= urb->transfer_buffer_length)
-                        use_sg = false;
+                        qh->use_sg = false;
         }
 
         musb_ep_select(mbase, epnum);
@@ -1552,7 +1551,6 @@ void musb_host_rx(struct musb *musb, u8 epnum)
         bool                    done = false;
         u32                     status;
         struct dma_channel      *dma;
-        static bool use_sg;
         unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
 
         musb_ep_select(mbase, epnum);
@@ -1878,12 +1876,12 @@ void musb_host_rx(struct musb *musb, u8 epnum)
                          * NULL.
                          */
                         if (!urb->transfer_buffer) {
-                                use_sg = true;
+                                qh->use_sg = true;
                                 sg_miter_start(&qh->sg_miter, urb->sg, 1,
                                                 sg_flags);
                         }
 
-                        if (use_sg) {
+                        if (qh->use_sg) {
                                 if (!sg_miter_next(&qh->sg_miter)) {
                                         dev_err(musb->controller, "error: sg list empty\n");
                                         sg_miter_stop(&qh->sg_miter);
@@ -1913,8 +1911,8 @@ finish:
         urb->actual_length += xfer_len;
         qh->offset += xfer_len;
         if (done) {
-                if (use_sg)
-                        use_sg = false;
+                if (qh->use_sg)
+                        qh->use_sg = false;
 
                 if (urb->status == -EINPROGRESS)
                         urb->status = status;
diff --git a/drivers/usb/musb/musb_host.h b/drivers/usb/musb/musb_host.h
index 5a9c8feec10c..738f7eb60df9 100644
--- a/drivers/usb/musb/musb_host.h
+++ b/drivers/usb/musb/musb_host.h
@@ -74,6 +74,7 @@ struct musb_qh {
         u16                     frame;          /* for periodic schedule */
         unsigned                iso_idx;        /* in urb->iso_frame_desc[] */
         struct sg_mapping_iter sg_miter;        /* for highmem in PIO mode */
+        bool                    use_sg;         /* to track urb using sglist */
 };
 
 /* map from control or bulk queue head to the first qh on that ring */