Hello. On 05/23/2014 04:57 PM, Daniel Mack wrote:
The datasheet says that MUSB_TXCSR_FLUSHFIFO is only valid when MUSB_CSR0_TXPKTRDY is set as well. Also, clear the MUSB_TXCSR_H_RXSTALL which drivers are not supposed to write,
I'd say "to set" ISO "to write" -- the bit still is clearable by the driver.
You're referring to the wording in the commit log? I can fix that, sure.
Yes, of course.
according to the docs.
Looks like the new code is contrariwise not clearing the stall.
I I'd say it's not supposed to. I just wanted the bit to be 0 when writing back the CSR.
You failed to achieve that since you forgot ~; you're clearing all bits but this one.
IOW, it follows the advisory in the datasheet that says: "You should clear this bit."
It only makes sense to clear it in the interrupt handler I think.
With this patch applied, the warning in this function does no longer kick in when an USB soundcard is unplugged while the stream is active.
Signed-off-by: Daniel Mack <zon...@gmail.com> --- drivers/usb/musb/musb_host.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index f98a7c0..9d3a5b2 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -120,7 +120,8 @@ static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep) if (csr != lastcsr) dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr); lastcsr = csr; - csr |= MUSB_TXCSR_FLUSHFIFO; + csr &= MUSB_TXCSR_H_RXSTALL; + csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_CSR0_TXPKTRDY;
Yes, the manual tells us to set TxPktRdy along with FlushFIFO. This has been a long standing bug, perhaps because the old versions of the MUSBHDRC manuals didn't mention that.
musb_writew(epio, MUSB_TXCSR, csr); csr = musb_readw(epio, MUSB_TXCSR);
Another possible bug here is not flushing the second FIFO in the double-buffered mode...
if (WARN(retries-- < 1,
I guess you meant this WARN()?
Jup. It's easy to reproduce btw, presumably with any off-the-shelf USB audio card, connected to something like the BBB.
BBB? My guess would be the bulk-only transport for the USB storage devices...
Thanks, Daniel
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