usb: musb: maintain three states for buffer mappings instead of two

If dma buffers are mapped by a higher layer, with a boolean musb_request.mapped
it is still possible to call dma_sync_single_for_device() from
musb_g_giveback(), even if txstate()/rxstate() has called unmap_dma_buffer()
before falling back to pio mode.

Moreover, check for musb_ep->dma is moved within map_dma_buffer() so where
applicable checks for it are removed. And where possible, checks for
is_dma_capable() are merged with buffer map state check.

Signed-off-by: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 32 insertions, 21 deletions

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 23dad4c8785d..65775039d6b3 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -92,11 +92,19 @@
 
 /* ----------------------------------------------------------------------- */
 
+#define is_buffer_mapped(req) (is_dma_capable() && \
+                                        (req->map_state != UN_MAPPED))
+
 /* Maps the buffer to dma  */
 
 static inline void map_dma_buffer(struct musb_request *request,
-                                struct musb *musb)
+                        struct musb *musb, struct musb_ep *musb_ep)
 {
+        request->map_state = UN_MAPPED;
+
+        if (!is_dma_capable() || !musb_ep->dma)
+                return;
+
         if (request->request.dma == DMA_ADDR_INVALID) {
                 request->request.dma = dma_map_single(
                                 musb->controller,
@@ -105,7 +113,7 @@ static inline void map_dma_buffer(struct musb_request *request,
                                 request->tx
                                         ? DMA_TO_DEVICE
                                         : DMA_FROM_DEVICE);
-                request->mapped = 1;
+                request->map_state = MUSB_MAPPED;
         } else {
                 dma_sync_single_for_device(musb->controller,
                         request->request.dma,
@@ -113,7 +121,7 @@ static inline void map_dma_buffer(struct musb_request *request,
                         request->tx
                                 ? DMA_TO_DEVICE
                                 : DMA_FROM_DEVICE);
-                request->mapped = 0;
+                request->map_state = PRE_MAPPED;
         }
 }
 
@@ -121,11 +129,14 @@ static inline void map_dma_buffer(struct musb_request *request,
 static inline void unmap_dma_buffer(struct musb_request *request,
                                 struct musb *musb)
 {
+        if (!is_buffer_mapped(request))
+                return;
+
         if (request->request.dma == DMA_ADDR_INVALID) {
                 DBG(20, "not unmapping a never mapped buffer\n");
                 return;
         }
-        if (request->mapped) {
+        if (request->map_state == MUSB_MAPPED) {
                 dma_unmap_single(musb->controller,
                         request->request.dma,
                         request->request.length,
@@ -133,16 +144,15 @@ static inline void unmap_dma_buffer(struct musb_request *request,
                                 ? DMA_TO_DEVICE
                                 : DMA_FROM_DEVICE);
                 request->request.dma = DMA_ADDR_INVALID;
-                request->mapped = 0;
-        } else {
+        } else { /* PRE_MAPPED */
                 dma_sync_single_for_cpu(musb->controller,
                         request->request.dma,
                         request->request.length,
                         request->tx
                                 ? DMA_TO_DEVICE
                                 : DMA_FROM_DEVICE);
-
         }
+        request->map_state = UN_MAPPED;
 }
 
 /*
@@ -172,8 +182,7 @@ __acquires(ep->musb->lock)
 
         ep->busy = 1;
         spin_unlock(&musb->lock);
-        if (is_dma_capable() && ep->dma)
-                unmap_dma_buffer(req, musb);
+        unmap_dma_buffer(req, musb);
         if (request->status == 0)
                 DBG(5, "%s done request %p,  %d/%d\n",
                                 ep->end_point.name, request,
@@ -335,7 +344,7 @@ static void txstate(struct musb *musb, struct musb_request *req)
                         csr);
 
 #ifndef CONFIG_MUSB_PIO_ONLY
-        if (is_dma_capable() && musb_ep->dma) {
+        if (is_buffer_mapped(req)) {
                 struct dma_controller   *c = musb->dma_controller;
                 size_t request_size;
 
@@ -436,8 +445,7 @@ static void txstate(struct musb *musb, struct musb_request *req)
                  * Unmap the dma buffer back to cpu if dma channel
                  * programming fails
                  */
-                if (is_dma_capable() && musb_ep->dma)
-                        unmap_dma_buffer(req, musb);
+                unmap_dma_buffer(req, musb);
 
                 musb_write_fifo(musb_ep->hw_ep, fifo_count,
                                 (u8 *) (request->buf + request->actual));
@@ -627,7 +635,7 @@ static void rxstate(struct musb *musb, struct musb_request *req)
                 return;
         }
 
-        if (is_cppi_enabled() && musb_ep->dma) {
+        if (is_cppi_enabled() && is_buffer_mapped(req)) {
                 struct dma_controller   *c = musb->dma_controller;
                 struct dma_channel      *channel = musb_ep->dma;
 
@@ -658,7 +666,7 @@ static void rxstate(struct musb *musb, struct musb_request *req)
                 len = musb_readw(epio, MUSB_RXCOUNT);
                 if (request->actual < request->length) {
 #ifdef CONFIG_USB_INVENTRA_DMA
-                        if (is_dma_capable() && musb_ep->dma) {
+                        if (is_buffer_mapped(req)) {
                                 struct dma_controller   *c;
                                 struct dma_channel      *channel;
                                 int                     use_dma = 0;
@@ -742,7 +750,7 @@ static void rxstate(struct musb *musb, struct musb_request *req)
                         fifo_count = min_t(unsigned, len, fifo_count);
 
 #ifdef  CONFIG_USB_TUSB_OMAP_DMA
-                        if (tusb_dma_omap() && musb_ep->dma) {
+                        if (tusb_dma_omap() && is_buffer_mapped(req)) {
                                 struct dma_controller *c = musb->dma_controller;
                                 struct dma_channel *channel = musb_ep->dma;
                                 u32 dma_addr = request->dma + request->actual;
@@ -762,7 +770,7 @@ static void rxstate(struct musb *musb, struct musb_request *req)
                          * programming fails. This buffer is mapped if the
                          * channel allocation is successful
                          */
-                         if (is_dma_capable() && musb_ep->dma) {
+                         if (is_buffer_mapped(req)) {
                                 unmap_dma_buffer(req, musb);
 
                                 /*
@@ -1222,10 +1230,7 @@ static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
         request->epnum = musb_ep->current_epnum;
         request->tx = musb_ep->is_in;
 
-        if (is_dma_capable() && musb_ep->dma)
-                map_dma_buffer(request, musb);
-        else
-                request->mapped = 0;
+        map_dma_buffer(request, musb, musb_ep);
 
         spin_lock_irqsave(&musb->lock, lockflags);
 
diff --git a/drivers/usb/musb/musb_gadget.h b/drivers/usb/musb/musb_gadget.h
index dec8dc008191..a55354fbccf5 100644
--- a/drivers/usb/musb/musb_gadget.h
+++ b/drivers/usb/musb/musb_gadget.h
@@ -35,13 +35,19 @@
 #ifndef __MUSB_GADGET_H
 #define __MUSB_GADGET_H
 
+enum buffer_map_state {
+        UN_MAPPED = 0,
+        PRE_MAPPED,
+        MUSB_MAPPED
+};
+
 struct musb_request {
         struct usb_request      request;
         struct musb_ep          *ep;
         struct musb             *musb;
         u8 tx;                  /* endpoint direction */
         u8 epnum;
-        u8 mapped;
+        enum buffer_map_state map_state;
 };
 
 static inline struct musb_request *to_musb_request(struct usb_request *req)