[PATCH 1/2] usb: musb: Fix DMA for host mode

From: Joshua Henderson
Date: Mon Feb 01 2016 - 19:34:24 EST


From: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>

Commit ac33cdb166811223cc (usb: musb: Remove ifdefs for musb_host_rx in
musb_host.c part5) introduces a problem setting DMA host mode.

This fixes the done condition that advances the musb schedule. Without this
patch the the msub_advance_schedule() is called immediately after receiving an
endpoint rx interrupt without waiting for the dma transfer to complete. As a
consequence when the dma complete interrupt arrives the in_qh member of hw_ep
is already null an the musb_host_rx() exits on !urb error case.

Signed-off-by: Cristian Birsan <cristian.birsan@xxxxxxxxxxxxx>
Signed-off-by: Joshua Henderson <joshua.henderson@xxxxxxxxxxxxx>
---
drivers/usb/musb/musb_host.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 795a45b..3fdc99b 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -1825,6 +1825,7 @@ void musb_host_rx(struct musb *musb, u8 epnum)
u16 rx_csr, val;
bool iso_err = false;
bool done = false;
+ int ret;
u32 status;
struct dma_channel *dma;
unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
@@ -2003,10 +2004,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
qh->offset,
urb->transfer_buffer_length);

- done = musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh,
+ ret = musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh,
urb, xfer_len,
iso_err);
- if (done)
+ if (ret)
goto finish;
else
dev_err(musb->controller, "error: rx_dma failed\n");
--
1.7.9.5