4 files changed, 37 insertions, 9 deletions

diff --git a/drivers/usb/musb/am35x.c b/drivers/usb/musb/am35x.c
index 457f25e62c51..c964d6af178b 100644
--- a/drivers/usb/musb/am35x.c
+++ b/drivers/usb/musb/am35x.c
@@ -305,6 +305,12 @@ static irqreturn_t am35x_musb_interrupt(int irq, void *hci)
                 ret = IRQ_HANDLED;
         }
 
+        /* Drop spurious RX and TX if device is disconnected */
+        if (musb->int_usb & MUSB_INTR_DISCONNECT) {
+                musb->int_tx = 0;
+                musb->int_rx = 0;
+        }
+
         if (musb->int_tx || musb->int_rx || musb->int_usb)
                 ret |= musb_interrupt(musb);
 
diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index 444346e1e10d..ff5f112053d2 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -458,11 +458,11 @@ static int __devinit dsps_create_musb_pdev(struct dsps_glue *glue, u8 id)
         struct platform_device  *musb;
         struct resource *res;
         struct resource resources[2];
-        char res_name[10];
+        char res_name[11];
         int ret, musbid;
 
         /* get memory resource */
-        sprintf(res_name, "musb%d", id);
+        snprintf(res_name, sizeof(res_name), "musb%d", id);
         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, res_name);
         if (!res) {
                 dev_err(dev, "%s get mem resource failed\n", res_name);
@@ -473,7 +473,7 @@ static int __devinit dsps_create_musb_pdev(struct dsps_glue *glue, u8 id)
         resources[0] = *res;
 
         /* get irq resource */
-        sprintf(res_name, "musb%d-irq", id);
+        snprintf(res_name, sizeof(res_name), "musb%d-irq", id);
         res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, res_name);
         if (!res) {
                 dev_err(dev, "%s get irq resource failed\n", res_name);
@@ -530,7 +530,7 @@ static int __devinit dsps_create_musb_pdev(struct dsps_glue *glue, u8 id)
 
                 of_property_read_u32(np, "num-eps", (u32 *)&config->num_eps);
                 of_property_read_u32(np, "ram-bits", (u32 *)&config->ram_bits);
-                sprintf(res_name, "port%d-mode", id);
+                snprintf(res_name, sizeof(res_name), "port%d-mode", id);
                 of_property_read_u32(np, res_name, (u32 *)&pdata->mode);
                 of_property_read_u32(np, "power", (u32 *)&pdata->power);
                 config->multipoint = of_property_read_bool(np, "multipoint");
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index d0b87e7b4abf..b6b84dacc791 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -707,11 +707,12 @@ static void rxstate(struct musb *musb, struct musb_request *req)
                 fifo_count = musb_readw(epio, MUSB_RXCOUNT);
 
                 /*
-                 *  use mode 1 only if we expect data of at least ep packet_sz
-                 *  and have not yet received a short packet
+                 * Enable Mode 1 on RX transfers only when short_not_ok flag
+                 * is set. Currently short_not_ok flag is set only from
+                 * file_storage and f_mass_storage drivers
                  */
-                if ((request->length - request->actual >= musb_ep->packet_sz) &&
-                        (fifo_count >= musb_ep->packet_sz))
+
+                if (request->short_not_ok && fifo_count == musb_ep->packet_sz)
                         use_mode_1 = 1;
                 else
                         use_mode_1 = 0;
@@ -727,6 +728,27 @@ static void rxstate(struct musb *musb, struct musb_request *req)
                                 c = musb->dma_controller;
                                 channel = musb_ep->dma;
 
+        /* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
+         * mode 0 only. So we do not get endpoint interrupts due to DMA
+         * completion. We only get interrupts from DMA controller.
+         *
+         * We could operate in DMA mode 1 if we knew the size of the tranfer
+         * in advance. For mass storage class, request->length = what the host
+         * sends, so that'd work.  But for pretty much everything else,
+         * request->length is routinely more than what the host sends. For
+         * most these gadgets, end of is signified either by a short packet,
+         * or filling the last byte of the buffer.  (Sending extra data in
+         * that last pckate should trigger an overflow fault.)  But in mode 1,
+         * we don't get DMA completion interrupt for short packets.
+         *
+         * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
+         * to get endpoint interrupt on every DMA req, but that didn't seem
+         * to work reliably.
+         *
+         * REVISIT an updated g_file_storage can set req->short_not_ok, which
+         * then becomes usable as a runtime "use mode 1" hint...
+         */
+
                                 /* Experimental: Mode1 works with mass storage use cases */
                                 if (use_mode_1) {
                                         csr |= MUSB_RXCSR_AUTOCLEAR;
diff --git a/drivers/usb/musb/ux500.c b/drivers/usb/musb/ux500.c
index d62a91fedc22..0e62f504410e 100644
--- a/drivers/usb/musb/ux500.c
+++ b/drivers/usb/musb/ux500.c
@@ -65,7 +65,7 @@ static int __devinit ux500_probe(struct platform_device *pdev)
         struct platform_device          *musb;
         struct ux500_glue               *glue;
         struct clk                      *clk;
-
+        int                             musbid;
         int                             ret = -ENOMEM;
 
         glue = kzalloc(sizeof(*glue), GFP_KERNEL);