From 92d2711f5dc15bf956546923a5718e74853f9912 Mon Sep 17 00:00:00 2001 From: Hema Kalliguddi Date: Mon, 15 Nov 2010 04:24:01 -0600 Subject: usb: musb: unmap dma buffer when switching to PIO Buffer is mapped to dma when dma channel is allocated. If, for some reason, dma channel programming fails, musb code will fallback to PIO mode to transfer that request. In that case, we need to unmap the buffer back to CPU. MUSB RTL1.8 and above cannot handle buffers which are not 32bit aligned. That happens to every request sent by g_ether gadget driver. Since the buffer sent was unaligned, we need to fallback to PIO. Because of that, g_ether was failing due to missing buffer unmapping. With this patch and [1] g_ether works fine with all MUSB revisions. Verified with OMAP3630 board, which has MUSB RTL1.8 using g_ether and g_zero. [1] http://www.spinics.net/lists/linux-usb/msg38400.html Signed-off-by: Hema HK Signed-off-by: Felipe Balbi --- drivers/usb/musb/musb_gadget.c | 117 ++++++++++++++++++++++++++++------------- 1 file changed, 79 insertions(+), 38 deletions(-) (limited to 'drivers/usb') diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index 36cfd06..0169dcf 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -92,6 +92,59 @@ /* ----------------------------------------------------------------------- */ +/* Maps the buffer to dma */ + +static inline void map_dma_buffer(struct musb_request *request, + struct musb *musb) +{ + if (request->request.dma == DMA_ADDR_INVALID) { + request->request.dma = dma_map_single( + musb->controller, + request->request.buf, + request->request.length, + request->tx + ? DMA_TO_DEVICE + : DMA_FROM_DEVICE); + request->mapped = 1; + } else { + dma_sync_single_for_device(musb->controller, + request->request.dma, + request->request.length, + request->tx + ? DMA_TO_DEVICE + : DMA_FROM_DEVICE); + request->mapped = 0; + } +} + +/* Unmap the buffer from dma and maps it back to cpu */ +static inline void unmap_dma_buffer(struct musb_request *request, + struct musb *musb) +{ + if (request->request.dma == DMA_ADDR_INVALID) { + DBG(20, "not unmapping a never mapped buffer\n"); + return; + } + if (request->mapped) { + dma_unmap_single(musb->controller, + request->request.dma, + request->request.length, + request->tx + ? DMA_TO_DEVICE + : DMA_FROM_DEVICE); + request->request.dma = DMA_ADDR_INVALID; + request->mapped = 0; + } else { + dma_sync_single_for_cpu(musb->controller, + request->request.dma, + request->request.length, + request->tx + ? DMA_TO_DEVICE + : DMA_FROM_DEVICE); + + } +} + /* * Immediately complete a request. * @@ -119,24 +172,8 @@ __acquires(ep->musb->lock) ep->busy = 1; spin_unlock(&musb->lock); - if (is_dma_capable()) { - if (req->mapped) { - dma_unmap_single(musb->controller, - req->request.dma, - req->request.length, - req->tx - ? DMA_TO_DEVICE - : DMA_FROM_DEVICE); - req->request.dma = DMA_ADDR_INVALID; - req->mapped = 0; - } else if (req->request.dma != DMA_ADDR_INVALID) - dma_sync_single_for_cpu(musb->controller, - req->request.dma, - req->request.length, - req->tx - ? DMA_TO_DEVICE - : DMA_FROM_DEVICE); - } + if (is_dma_capable() && ep->dma) + unmap_dma_buffer(req, musb); if (request->status == 0) DBG(5, "%s done request %p, %d/%d\n", ep->end_point.name, request, @@ -395,6 +432,13 @@ static void txstate(struct musb *musb, struct musb_request *req) #endif if (!use_dma) { + /* + * Unmap the dma buffer back to cpu if dma channel + * programming fails + */ + if (is_dma_capable() && musb_ep->dma) + unmap_dma_buffer(req, musb); + musb_write_fifo(musb_ep->hw_ep, fifo_count, (u8 *) (request->buf + request->actual)); request->actual += fifo_count; @@ -713,6 +757,20 @@ static void rxstate(struct musb *musb, struct musb_request *req) return; } #endif + /* + * Unmap the dma buffer back to cpu if dma channel + * programming fails. This buffer is mapped if the + * channel allocation is successful + */ + if (is_dma_capable() && musb_ep->dma) { + unmap_dma_buffer(req, musb); + + /* Clear DMAENAB for the + * PIO mode transfer + */ + csr &= ~MUSB_RXCSR_DMAENAB; + musb_writew(epio, MUSB_RXCSR, csr); + } musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *) (request->buf + request->actual)); @@ -1150,26 +1208,9 @@ 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) { - if (request->request.dma == DMA_ADDR_INVALID) { - request->request.dma = dma_map_single( - musb->controller, - request->request.buf, - request->request.length, - request->tx - ? DMA_TO_DEVICE - : DMA_FROM_DEVICE); - request->mapped = 1; - } else { - dma_sync_single_for_device(musb->controller, - request->request.dma, - request->request.length, - request->tx - ? DMA_TO_DEVICE - : DMA_FROM_DEVICE); - request->mapped = 0; - } - } else + if (is_dma_capable() && musb_ep->dma) + map_dma_buffer(request, musb); + else request->mapped = 0; spin_lock_irqsave(&musb->lock, lockflags); -- cgit v1.1 From e75df37165c639b06213ec88b4763c3e50a7f079 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Tue, 16 Nov 2010 23:37:37 +0800 Subject: usb: musb: clear RXCSR_AUTOCLEAR before PIO read If RXCSR_AUTOCLEAR flag is not cleard before PIO reading, one packet may be recieved by musb fifo, but no chance to notify software, so cause packet loss, follows the detailed process: - PIO read one packet - musb fifo auto clear the MUSB_RXCSR_RXPKTRDY - musb continue to recieve the next packet, and MUSB_RXCSR_RXPKTRDY is set - software clear the MUSB_RXCSR_RXPKTRDY, so there is no chance for musb to notify software that the 2nd recieved packet. The patch does fix the g_ether issue below: - use fifo_mode 3 to enable double buffer - 'ping -s 1024 IP_OF_BEAGLE_XM' - one usb packet of 512 byte is lost, so ping failed, which can be observed by wireshark note: Beagle xm takes musb rtl1.8 and may fallback to pio mode for unaligned buffer. Signed-off-by: Ming Lei Signed-off-by: Felipe Balbi --- drivers/usb/musb/musb_gadget.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/usb') diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index 0169dcf..363cfad 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -765,10 +765,11 @@ static void rxstate(struct musb *musb, struct musb_request *req) if (is_dma_capable() && musb_ep->dma) { unmap_dma_buffer(req, musb); - /* Clear DMAENAB for the + /* + * Clear DMAENAB and AUTOCLEAR for the * PIO mode transfer */ - csr &= ~MUSB_RXCSR_DMAENAB; + csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR); musb_writew(epio, MUSB_RXCSR, csr); } -- cgit v1.1 From bb324b08165d5656d221af013ed9994a54e455be Mon Sep 17 00:00:00 2001 From: Ajay Kumar Gupta Date: Mon, 22 Nov 2010 14:22:41 +0530 Subject: usb: musb: gadget: fix compilation warning Fixes below compilation warning when musb driver is compiled for PIO mode: drivers/usb/musb/musb_gadget.c: In function 'musb_g_rx': drivers/usb/musb/musb_gadget.c:840: warning: label 'exit' defined but not used Signed-off-by: Ajay Kumar Gupta Signed-off-by: Felipe Balbi --- drivers/usb/musb/musb_gadget.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/usb') diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index 363cfad..c8de0e1 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -896,7 +896,9 @@ void musb_g_rx(struct musb *musb, u8 epnum) if (!request) return; } +#if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) exit: +#endif /* Analyze request */ rxstate(musb, to_musb_request(request)); } -- cgit v1.1 From 07a8cdd2bb17a4da68136d963b8bc71959bd31a5 Mon Sep 17 00:00:00 2001 From: Anand Gadiyar Date: Thu, 18 Nov 2010 18:54:17 +0530 Subject: usb: musb: do not use dma for control transfers The Inventra DMA engine used with the MUSB controller in many SoCs cannot use DMA for control transfers on EP0, but can use DMA for all other transfers. The USB core maps urbs for DMA if hcd->self.uses_dma is true. (hcd->self.uses_dma is true for MUSB as well). Split the uses_dma flag into two - one that says if the controller needs to use PIO for control transfers, and another which says if the controller uses DMA (for all other transfers). Also, populate this flag for all MUSB by default. (Tested on OMAP3 and OMAP4 boards, with EHCI and MUSB HCDs simultaneously in use). Signed-off-by: Maulik Mankad Signed-off-by: Santosh Shilimkar Signed-off-by: Anand Gadiyar Cc: Oliver Neukum Cc: Alan Stern Cc: Praveena NADAHALLY Cc: Ajay Kumar Gupta Signed-off-by: Felipe Balbi --- drivers/usb/core/hcd.c | 2 ++ drivers/usb/musb/musb_core.c | 3 +++ drivers/usb/musb/musb_gadget.c | 4 ++++ 3 files changed, 9 insertions(+) (limited to 'drivers/usb') diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 61800f7..ced846a 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1330,6 +1330,8 @@ static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, */ if (usb_endpoint_xfer_control(&urb->ep->desc)) { + if (hcd->self.uses_pio_for_control) + return ret; if (hcd->self.uses_dma) { urb->setup_dma = dma_map_single( hcd->self.controller, diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c index e6669fc..99beebc 100644 --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -2116,12 +2116,15 @@ bad_config: * Otherwise, wait till the gadget driver hooks up. */ if (!is_otg_enabled(musb) && is_host_enabled(musb)) { + struct usb_hcd *hcd = musb_to_hcd(musb); + MUSB_HST_MODE(musb); musb->xceiv->default_a = 1; musb->xceiv->state = OTG_STATE_A_IDLE; status = usb_add_hcd(musb_to_hcd(musb), -1, 0); + hcd->self.uses_pio_for_control = 1; DBG(1, "%s mode, status %d, devctl %02x %c\n", "HOST", status, musb_readb(musb->mregs, MUSB_DEVCTL), diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index c8de0e1..9d6ade8 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -1833,6 +1833,8 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver, spin_unlock_irqrestore(&musb->lock, flags); if (is_otg_enabled(musb)) { + struct usb_hcd *hcd = musb_to_hcd(musb); + DBG(3, "OTG startup...\n"); /* REVISIT: funcall to other code, which also @@ -1847,6 +1849,8 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver, musb->gadget_driver = NULL; musb->g.dev.driver = NULL; spin_unlock_irqrestore(&musb->lock, flags); + } else { + hcd->self.uses_pio_for_control = 1; } } } -- cgit v1.1