As blackfin doesn't support double buffering feature as of today.
It used to use
Commit 9f445cb [USB: musb: disable double buffering for older RTL versions] to
skip this problem, but which caused other problem.
eg: As Ajay pointed out "breaking the high bandwidth isochronous transfer" and
Ming pointed "break full speed and cause overflow problems".
So add a flag set by musb_platform_init() to force fully disable that feature.
Such flag is created and marked as deprecated to force to find a solution for
the missing double buffering support on blackfin.
Signed-off-by: Bob Liu <lliubbo@xxxxxxxxx>
---
drivers/usb/musb/blackfin.c | 1 +
drivers/usb/musb/musb_core.h | 12 ++++++++++++
drivers/usb/musb/musb_gadget.c | 10 ++++++++--
drivers/usb/musb/musb_host.c | 2 +-
4 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/musb/blackfin.c b/drivers/usb/musb/blackfin.c
index eeba228..9d49d1c 100644
--- a/drivers/usb/musb/blackfin.c
+++ b/drivers/usb/musb/blackfin.c
@@ -404,6 +404,7 @@ static int bfin_musb_init(struct musb *musb)
musb->xceiv->set_power = bfin_musb_set_power;
musb->isr = blackfin_interrupt;
+ musb->double_buffer_not_ok = true;
return 0;
}
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index d0c236f..d74a811 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -488,6 +488,18 @@ struct musb {
unsigned set_address:1;
unsigned test_mode:1;
unsigned softconnect:1;
+ /*
+ * FIXME: Remove this flag.
+ *
+ * This is only added to allow Blackfin to work
+ * with current driver. For some unknown reason
+ * Blackfin doesn't work with double buffering
+ * and that's enabled by default.
+ *
+ * We added this flag to forcefully disable double
+ * buffering until we get it working.
+ */
+ unsigned double_buffer_not_ok:1 __deprecated;
u8 address;
u8 test_mode_nr;
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index ed58c6c..bee8106 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -989,7 +989,10 @@ static int musb_gadget_enable(struct usb_ep *ep,
/* Set TXMAXP with the FIFO size of the endpoint
* to disable double buffering mode.
*/
- musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
+ if (musb->double_buffer_not_ok)
+ musb_writew(regs, MUSB_TXMAXP, hw_ep->max_packet_sz_tx);
+ else
+ musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
if (musb_readw(regs, MUSB_TXCSR)
@@ -1025,7 +1028,10 @@ static int musb_gadget_enable(struct usb_ep *ep,
/* Set RXMAXP with the FIFO size of the endpoint
* to disable double buffering mode.
*/
- musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
+ if (musb->double_buffer_not_ok)
+ musb_writew(regs, MUSB_RXMAXP, hw_ep->max_packet_sz_tx);
+ else
+ musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
/* force shared fifo to OUT-only mode */
if (hw_ep->is_shared_fifo) {
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index 4d5bcb4..7a9ab45 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -609,7 +609,7 @@ musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
/* Set RXMAXP with the FIFO size of the endpoint
* to disable double buffer mode.
*/
- if (musb->hwvers < MUSB_HWVERS_2000)
+ if (musb->double_buffer_not_ok)
musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
else
musb_writew(ep->regs, MUSB_RXMAXP,
--
1.6.3.3
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