3 files changed, 30 insertions, 14 deletions

diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
index 1f2037bbeb0d..45c83baf675d 100644
--- a/drivers/usb/musb/Kconfig
+++ b/drivers/usb/musb/Kconfig
@@ -159,7 +159,7 @@ config USB_TI_CPPI_DMA
 
 config USB_TI_CPPI41_DMA
 	bool 'TI CPPI 4.1 (AM335x)'
-	depends on ARCH_OMAP
+	depends on ARCH_OMAP && DMADEVICES
 	select TI_CPPI41
 
 config USB_TUSB_OMAP_DMA
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index ba13529cbd52..ee9ff7028b92 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -132,7 +132,7 @@ static inline struct musb *dev_to_musb(struct device *dev)
 /*-------------------------------------------------------------------------*/
 
 #ifndef CONFIG_BLACKFIN
-static int musb_ulpi_read(struct usb_phy *phy, u32 offset)
+static int musb_ulpi_read(struct usb_phy *phy, u32 reg)
 {
 	void __iomem *addr = phy->io_priv;
 	int	i = 0;
@@ -151,7 +151,7 @@ static int musb_ulpi_read(struct usb_phy *phy, u32 offset)
 	 * ULPICarKitControlDisableUTMI after clearing POWER_SUSPENDM.
 	 */
 
-	musb_writeb(addr, MUSB_ULPI_REG_ADDR, (u8)offset);
+	musb_writeb(addr, MUSB_ULPI_REG_ADDR, (u8)reg);
 	musb_writeb(addr, MUSB_ULPI_REG_CONTROL,
 			MUSB_ULPI_REG_REQ | MUSB_ULPI_RDN_WR);
 
@@ -176,7 +176,7 @@ out:
 	return ret;
 }
 
-static int musb_ulpi_write(struct usb_phy *phy, u32 offset, u32 data)
+static int musb_ulpi_write(struct usb_phy *phy, u32 val, u32 reg)
 {
 	void __iomem *addr = phy->io_priv;
 	int	i = 0;
@@ -191,8 +191,8 @@ static int musb_ulpi_write(struct usb_phy *phy, u32 offset, u32 data)
 	power &= ~MUSB_POWER_SUSPENDM;
 	musb_writeb(addr, MUSB_POWER, power);
 
-	musb_writeb(addr, MUSB_ULPI_REG_ADDR, (u8)offset);
-	musb_writeb(addr, MUSB_ULPI_REG_DATA, (u8)data);
+	musb_writeb(addr, MUSB_ULPI_REG_ADDR, (u8)reg);
+	musb_writeb(addr, MUSB_ULPI_REG_DATA, (u8)val);
 	musb_writeb(addr, MUSB_ULPI_REG_CONTROL, MUSB_ULPI_REG_REQ);
 
 	while (!(musb_readb(addr, MUSB_ULPI_REG_CONTROL)
@@ -1668,7 +1668,7 @@ EXPORT_SYMBOL_GPL(musb_interrupt);
 static bool use_dma = 1;
 
 /* "modprobe ... use_dma=0" etc */
-module_param(use_dma, bool, 0);
+module_param(use_dma, bool, 0644);
 MODULE_PARM_DESC(use_dma, "enable/disable use of DMA");
 
 void musb_dma_completion(struct musb *musb, u8 epnum, u8 transmit)
@@ -2017,7 +2017,6 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
 	/* We need musb_read/write functions initialized for PM */
 	pm_runtime_use_autosuspend(musb->controller);
 	pm_runtime_set_autosuspend_delay(musb->controller, 200);
-	pm_runtime_irq_safe(musb->controller);
 	pm_runtime_enable(musb->controller);
 
 	/* The musb_platform_init() call:
@@ -2095,6 +2094,7 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
 #ifndef CONFIG_MUSB_PIO_ONLY
 	if (!musb->ops->dma_init || !musb->ops->dma_exit) {
 		dev_err(dev, "DMA controller not set\n");
+		status = -ENODEV;
 		goto fail2;
 	}
 	musb_dma_controller_create = musb->ops->dma_init;
@@ -2218,6 +2218,12 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
 
 	pm_runtime_put(musb->controller);
 
+	/*
+	 * For why this is currently needed, see commit 3e43a0725637
+	 * ("usb: musb: core: add pm_runtime_irq_safe()")
+	 */
+	pm_runtime_irq_safe(musb->controller);
+
 	return 0;
 
 fail5:
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 26c65e66cc0f..795a45b1b25b 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -112,22 +112,32 @@ static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
 	struct musb	*musb = ep->musb;
 	void __iomem	*epio = ep->regs;
 	u16		csr;
-	u16		lastcsr = 0;
 	int		retries = 1000;
 
 	csr = musb_readw(epio, MUSB_TXCSR);
 	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
-		if (csr != lastcsr)
-			dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
-		lastcsr = csr;
 		csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_TXPKTRDY;
 		musb_writew(epio, MUSB_TXCSR, csr);
 		csr = musb_readw(epio, MUSB_TXCSR);
-		if (WARN(retries-- < 1,
+
+		/*
+		 * FIXME: sometimes the tx fifo flush failed, it has been
+		 * observed during device disconnect on AM335x.
+		 *
+		 * To reproduce the issue, ensure tx urb(s) are queued when
+		 * unplug the usb device which is connected to AM335x usb
+		 * host port.
+		 *
+		 * I found using a usb-ethernet device and running iperf
+		 * (client on AM335x) has very high chance to trigger it.
+		 *
+		 * Better to turn on dev_dbg() in musb_cleanup_urb() with
+		 * CPPI enabled to see the issue when aborting the tx channel.
+		 */
+		if (dev_WARN_ONCE(musb->controller, retries-- < 1,
 				"Could not flush host TX%d fifo: csr: %04x\n",
 				ep->epnum, csr))
 			return;
-		mdelay(1);
 	}
 }