On Fri, Nov 5, 2010 at 8:58 PM, Felipe Balbi <balbi@xxxxxx> wrote:
> From: Ming Lei <tom.leiming@xxxxxxxxx>
>
> Commit 9f445cb29918dc488b7a9a92ef018599cce33df7[USB: musb: disable
> double buffering for older RTL versions] tries to disable double
> buffer mode by writing endpoint hw max packet size to TXMAP/RXMAP.
>
> First the approach can break full speed and cause overflow problems.
> We should always set those registers with the actual max packet size
> from endpoint descriptor.
>
> Second, the problem describe by commit 9f445cb29918dc488b7a9a92ef018599cce33df7
> was caused by musb gadget driver; nothing to do with RTL revision as
> originaly suspected.
>
> The real fix to the problem is to always use actual max packet
> size from endpoint descriptor to config TXMAP/RXMAP registers.
>
> Cc: Cliff Cai <cliff.cai@xxxxxxxxxx>
> Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
> Cc: Anand Gadiyar <gadiyar@xxxxxx>
> Cc: Mike Frysinger <vapier@xxxxxxxxxx>
> Cc: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxx
> Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
> Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> ---
> Âdrivers/usb/musb/musb_gadget.c | Â 13 +++----------
> Â1 files changed, 3 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
> index ba22e4a..f37b859 100644
> --- a/drivers/usb/musb/musb_gadget.c
> +++ b/drivers/usb/musb/musb_gadget.c
> @@ -926,13 +926,9 @@ static int musb_gadget_enable(struct usb_ep *ep,
> Â Â Â Â Â Â Â Â * likewise high bandwidth periodic tx
> Â Â Â Â Â Â Â Â */
> Â Â Â Â Â Â Â Â/* Set TXMAXP with the FIFO size of the endpoint
> - Â Â Â Â Â Â Â Â* to disable double buffering mode. Currently, It seems that double
> - Â Â Â Â Â Â Â Â* buffering has problem if musb RTL revision number < 2.0.
> + Â Â Â Â Â Â Â Â* to disable double buffering mode.
> Â Â Â Â Â Â Â Â */
> - Â Â Â Â Â Â Â if (musb->hwvers < MUSB_HWVERS_2000)
> - Â Â Â Â Â Â Â Â Â Â Â musb_writew(regs, MUSB_TXMAXP, hw_ep->max_packet_sz_tx);
> - Â Â Â Â Â Â Â else
> - Â Â Â Â Â Â Â Â Â Â Â musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
> + Â Â Â Â Â Â Â musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
>
> Â Â Â Â Â Â Â Âcsr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
> Â Â Â Â Â Â Â Âif (musb_readw(regs, MUSB_TXCSR)
> @@ -968,10 +964,7 @@ static int musb_gadget_enable(struct usb_ep *ep,
> Â Â Â Â Â Â Â Â/* Set RXMAXP with the FIFO size of the endpoint
> Â Â Â Â Â Â Â Â * to disable double buffering mode.
> Â Â Â Â Â Â Â Â */
> - Â Â Â Â Â Â Â if (musb->hwvers < MUSB_HWVERS_2000)
> - Â Â Â Â Â Â Â Â Â Â Â musb_writew(regs, MUSB_RXMAXP, hw_ep->max_packet_sz_rx);
> - Â Â Â Â Â Â Â else
> - Â Â Â Â Â Â Â Â Â Â Â musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
> + Â Â Â Â Â Â Â musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz | (musb_ep->hb_mult << 11));
>
> Â Â Â Â Â Â Â Â/* force shared fifo to OUT-only mode */
> Â Â Â Â Â Â Â Âif (hw_ep->is_shared_fifo) {
> --
> 1.7.3.2.146.gca209
>
> --
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>
Hi, Felipe
After apply this patch, we will still get data corruption on blackfin
platform(g_zero test)
even following all of MingLei's suggestion.
As you said
"NAK. I have observed data corruption when using double buffering on
tusb6010, omap3430 and omap3630."
when cliff first upload patch "USB: musb: disable double buffering for
older RTL versions".
link:http://marc.info/?l=linux-usb&m=126472940418964&w=2
So could you please confirm this issue?
This patch won't cause data corruption on tusb6010, omap3430 and
omap3630 any more?
Thanks.
--
--Bob
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