[PATCH 4/4] usb: musb: musb_cppi41: Workaround dma stall issue during teardown

[Alexandre Bailon <abailon-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>]

The dma may hung up if a teardown is initiated while an endpoint is still
active (Advisory 2.3.27 of da8xx errata).
To workaround this issue, add a delay before to initiate the teardown.

Signed-off-by: Alexandre Bailon <abailon-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
---
 drivers/usb/musb/da8xx.c       | 2 +-
 drivers/usb/musb/musb_core.h   | 1 +
 drivers/usb/musb/musb_cppi41.c | 4 ++++
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
index 74dcc07..3513284 100644
--- a/drivers/usb/musb/da8xx.c
+++ b/drivers/usb/musb/da8xx.c
@@ -458,7 +458,7 @@ static inline u8 get_vbus_power(struct device *dev)
 }
 
 static const struct musb_platform_ops da8xx_ops = {
-	.quirks		= MUSB_DMA_CPPI41 | MUSB_INDEXED_EP,
+	.quirks		= MUSB_DMA_CPPI41 | MUSB_INDEXED_EP | MUSB_DA8XX,
 	.init		= da8xx_musb_init,
 	.exit		= da8xx_musb_exit,
 
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index ade902e..d129278 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -172,6 +172,7 @@ struct musb_io;
  */
 struct musb_platform_ops {
 
+#define MUSB_DA8XX		BIT(7)
 #define MUSB_DMA_UX500		BIT(6)
 #define MUSB_DMA_CPPI41		BIT(5)
 #define MUSB_DMA_CPPI		BIT(4)
diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index 1636385..8fdbc17 100644
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -547,6 +547,10 @@ static int cppi41_dma_channel_abort(struct dma_channel *channel)
 		}
 	}
 
+	/* DA8xx Advisory 2.3.27: wait 250 ms before to start the teardown */
+	if (musb->io.quirks & MUSB_DA8XX)
+		mdelay(250);
+
 	tdbit = 1 << cppi41_channel->port_num;
 	if (is_tx)
 		tdbit <<= 16;
-- 
2.10.2

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html