On Thu, Nov 25, 2010 at 06:24:46PM +0800, Ming Lei wrote:
2010/11/25 Anand Gadiyar <gadiyar@xxxxxx>:
Felipe Balbi wrote:
Hi,
On Thu, Nov 25, 2010 at 04:54:05PM +0800, Bob Liu wrote:
>>> The only work around is to config the receive FIFO into single
buffer
>>> mode.
>>
>> And how to do that ?
>>
>
>It's used to by "USB: musb: disable double buffering for older RTL
>versions"
http://git.kernel.org/?p=linux/kernel/git/next/linux-next.git;a=commitdif
f;h=9f445cb29918dc488b7a9a92ef018599cce33df7
yeah, but that breaks other stuff high bandwidth eps, so we need a
better way to "disable double buffering".
Here's how I understand the problem.
Blackfin has a statically configured fifo allocation - with no
possibility to change it. The IP uses double buffering by default
if a FIFO is allocated space enough to hold 2*maxp (which is the
case for at least some of the endpoints).
The only way to make the IP use single buffering is to tell the
IP that the maxp is different.
This is an anomaly only in the blackfin - I don't see any way to
work around this (for lack of information), than what has been
implemented in the patch that already got merged.
Yes, I agree.
However, that code should be made to execute only on blackfin
and not on other platforms - so that the others are not broken
by that change.
Even in blackfin platform, the code may break some function,
especially for full speed device, which was explained a lot in
the previous discussion:
how about something like:
From 0cbcba73308ca808d898c2b5d8220e3ff9f52e58 Mon Sep 17 00:00:00 2001
From: Felipe Balbi <balbi@xxxxxx>
Date: Thu, 18 Nov 2010 13:44:29 +0200
Subject: [PATCH] usb: musb: disable double buffer when it's broken
Organization: Texas Instruments\n
We know that blackfin doesn't support double
buffering feature as of today. So we add a
flag set by musb_platform_init() to forcefully
disable that feature.
Such flag is created and marked as deprecated
to force us to find a solution for the missing
double buffering support on blackfin.
NYET-Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
drivers/usb/musb/blackfin.c | 1 +
drivers/usb/musb/musb_core.h | 13 +++++++++++++
drivers/usb/musb/musb_gadget.c | 28 ++++++++++++++++++++++------
drivers/usb/musb/musb_host.c | 17 +++++++++--------
4 files changed, 45 insertions(+), 14 deletions(-)
diff --git a/drivers/usb/musb/blackfin.c b/drivers/usb/musb/blackfin.c
index fcb5206..dba1f63 100644
--- a/drivers/usb/musb/blackfin.c
+++ b/drivers/usb/musb/blackfin.c
@@ -397,6 +397,7 @@ int __init musb_platform_init(struct musb *musb, void *board_data)
musb->xceiv->set_power = bfin_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 febaabc..05cf5ef 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -443,6 +443,19 @@ struct musb {
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;
u16 ackpend; /* ep0 */
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 36cfd06..d6bfad8 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -925,10 +925,18 @@ static int musb_gadget_enable(struct usb_ep *ep,
/* REVISIT if can_bulk_split(), use by updating "tmp";
* likewise high bandwidth periodic tx
*/
- /* Set TXMAXP with the FIFO size of the endpoint
- * to disable double buffering mode.
+
+ /*
+ * At least blackfin doesn't like Double Buffering
+ * which is enabled by default. So check if we can
+ * support double buffering and set MaxPacket register
+ * accordingly.
*/
- 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, 1024);
+ 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)
@@ -961,10 +969,18 @@ static int musb_gadget_enable(struct usb_ep *ep,
/* REVISIT if can_bulk_combine() use by updating "tmp"
* likewise high bandwidth periodic rx
*/
- /* Set RXMAXP with the FIFO size of the endpoint
- * to disable double buffering mode.
+
+ /*
+ * At least blackfin doesn't like Double Buffering
+ * which is enabled by default. So check if we can
+ * support double buffering and MaxPacket register
+ * accordingly.
*/
- musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
+ if (musb->double_buffer_not_ok)
+ musb_writew(regs, MUSB_TXMAXP, 1024);
+ else
+ musb_writew(regs, MUSB_TXMAXP, 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..0484bad 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -606,11 +606,12 @@ musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
/* NOTE: bulk combining rewrites high bits of maxpacket */
- /* Set RXMAXP with the FIFO size of the endpoint
+ /*
+ * Set RXMAXP with the FIFO size of the endpoint
* to disable double buffer mode.
*/
- if (musb->hwvers < MUSB_HWVERS_2000)
- musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
+ if (musb->double_buffer_not_ok)
+ musb_writew(ep->regs, MUSB_RXMAXP, 1024);
else
musb_writew(ep->regs, MUSB_RXMAXP,
qh->maxpacket | ((qh->hb_mult - 1) << 11));
@@ -784,14 +785,14 @@ static void musb_ep_program(struct musb *musb, u8 epnum,
/* protocol/endpoint/interval/NAKlimit */
if (epnum) {
musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
- if (can_bulk_split(musb, qh->type))
+ if (musb->double_buffer_not_ok)
musb_writew(epio, MUSB_TXMAXP,
- packet_sz
- | ((hw_ep->max_packet_sz_tx /
- packet_sz) - 1) << 11);
+ 1024);
else
musb_writew(epio, MUSB_TXMAXP,
- packet_sz);
+ qh->maxpacket |
+ ((qh->hb_mult - 1) << 11));
+
musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
} else {
musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
--
1.7.3.2.245.g03276
--
balbi
--
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