From 92d2711f5dc15bf956546923a5718e74853f9912 Mon Sep 17 00:00:00 2001
From: Hema Kalliguddi <hemahk@ti.com>
Date: Mon, 15 Nov 2010 04:24:01 -0600
Subject: [PATCH 1/4] 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 <hemahk@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
drivers/usb/musb/musb_gadget.c | 117 ++++++++++++++++++++++-----------
1 file changed, 79 insertions(+), 38 deletions(-)
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 36cfd060dbe5..0169dcf3a6ff 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);
From e75df37165c639b06213ec88b4763c3e50a7f079 Mon Sep 17 00:00:00 2001
From: Ming Lei <tom.leiming@gmail.com>
Date: Tue, 16 Nov 2010 23:37:37 +0800
Subject: [PATCH 2/4] 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 <tom.leiming@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
drivers/usb/musb/musb_gadget.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 0169dcf3a6ff..363cfad003f8 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);
}
From bb324b08165d5656d221af013ed9994a54e455be Mon Sep 17 00:00:00 2001
From: Ajay Kumar Gupta <ajay.gupta@ti.com>
Date: Mon, 22 Nov 2010 14:22:41 +0530
Subject: [PATCH 3/4] 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 <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
drivers/usb/musb/musb_gadget.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 363cfad003f8..c8de0e123f2c 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));
}
From 07a8cdd2bb17a4da68136d963b8bc71959bd31a5 Mon Sep 17 00:00:00 2001
From: Anand Gadiyar <gadiyar@ti.com>
Date: Thu, 18 Nov 2010 18:54:17 +0530
Subject: [PATCH 4/4] 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 <x0082077@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Praveena NADAHALLY <praveen.nadahally@stericsson.com>
Cc: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
---
drivers/usb/core/hcd.c | 2 ++
drivers/usb/musb/musb_core.c | 3 +++
drivers/usb/musb/musb_gadget.c | 4 ++++
include/linux/usb.h | 4 ++++
4 files changed, 13 insertions(+)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 61800f77dac8..ced846ac4141 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 e6669fc3b804..99beebce8550 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2116,12 +2116,15 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
* 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 c8de0e123f2c..9d6ade82b9f2 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;
}
}
}
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 24300d8a1bc1..a28eb2592577 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -313,6 +313,10 @@ struct usb_bus {
int busnum; /* Bus number (in order of reg) */
const char *bus_name; /* stable id (PCI slot_name etc) */
u8 uses_dma; /* Does the host controller use DMA? */
+ u8 uses_pio_for_control; /*
+ * Does the host controller use PIO
+ * for control transfers?
+ */
u8 otg_port; /* 0, or number of OTG/HNP port */
unsigned is_b_host:1; /* true during some HNP roleswitches */
unsigned b_hnp_enable:1; /* OTG: did A-Host enable HNP? */