1 files changed, 22 insertions, 11 deletions

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index c7ebd0867fcc..f79440cdfe7e 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -165,9 +165,15 @@ static void nuke(struct musb_ep *ep, const int status)
         if (is_dma_capable() && ep->dma) {
                 struct dma_controller   *c = ep->musb->dma_controller;
                 int value;
+
                 if (ep->is_in) {
+                        /*
+                         * The programming guide says that we must not clear
+                         * the DMAMODE bit before DMAENAB, so we only
+                         * clear it in the second write...
+                         */
                         musb_writew(epio, MUSB_TXCSR,
-                                        0 | MUSB_TXCSR_FLUSHFIFO);
+                                    MUSB_TXCSR_DMAMODE | MUSB_TXCSR_FLUSHFIFO);
                         musb_writew(epio, MUSB_TXCSR,
                                         0 | MUSB_TXCSR_FLUSHFIFO);
                 } else {
@@ -230,7 +236,7 @@ static inline int max_ep_writesize(struct musb *musb, struct musb_ep *ep)
                   |     IN token(s) are recd from Host.
                   |             -> DMA interrupt on completion
                   |                calls TxAvail.
-                  |                   -> stop DMA, ~DmaEenab,
+                  |                   -> stop DMA, ~DMAENAB,
                   |                   -> set TxPktRdy for last short pkt or zlp
                   |                   -> Complete Request
                   |                   -> Continue next request (call txstate)
@@ -315,9 +321,17 @@ static void txstate(struct musb *musb, struct musb_request *req)
                                         request->dma, request_size);
                         if (use_dma) {
                                 if (musb_ep->dma->desired_mode == 0) {
-                                        /* ASSERT: DMAENAB is clear */
-                                        csr &= ~(MUSB_TXCSR_AUTOSET |
-                                                        MUSB_TXCSR_DMAMODE);
+                                        /*
+                                         * We must not clear the DMAMODE bit
+                                         * before the DMAENAB bit -- and the
+                                         * latter doesn't always get cleared
+                                         * before we get here...
+                                         */
+                                        csr &= ~(MUSB_TXCSR_AUTOSET
+                                                | MUSB_TXCSR_DMAENAB);
+                                        musb_writew(epio, MUSB_TXCSR, csr
+                                                | MUSB_TXCSR_P_WZC_BITS);
+                                        csr &= ~MUSB_TXCSR_DMAMODE;
                                         csr |= (MUSB_TXCSR_DMAENAB |
                                                         MUSB_TXCSR_MODE);
                                         /* against programming guide */
@@ -334,10 +348,7 @@ static void txstate(struct musb *musb, struct musb_request *req)
 
 #elif defined(CONFIG_USB_TI_CPPI_DMA)
                 /* program endpoint CSR first, then setup DMA */
-                csr &= ~(MUSB_TXCSR_AUTOSET
-                                | MUSB_TXCSR_DMAMODE
-                                | MUSB_TXCSR_P_UNDERRUN
-                                | MUSB_TXCSR_TXPKTRDY);
+                csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
                 csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_DMAENAB;
                 musb_writew(epio, MUSB_TXCSR,
                         (MUSB_TXCSR_P_WZC_BITS & ~MUSB_TXCSR_P_UNDERRUN)
@@ -364,8 +375,8 @@ static void txstate(struct musb *musb, struct musb_request *req)
                 if (!use_dma) {
                         c->channel_release(musb_ep->dma);
                         musb_ep->dma = NULL;
-                        /* ASSERT: DMAENAB clear */
-                        csr &= ~(MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
+                        csr &= ~MUSB_TXCSR_DMAENAB;
+                        musb_writew(epio, MUSB_TXCSR, csr);
                         /* invariant: prequest->buf is non-null */
                 }
 #elif defined(CONFIG_USB_TUSB_OMAP_DMA)