Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

[mirror_ubuntu-bionic-kernel.git] / drivers / usb / musb / musb_gadget.c

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index c7ebd0867fcca9281ecf25abc130c91389444240..f79440cdfe7ee2e346ae59cd2e164618c7d2a3f7 100644 (file)
--- 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)