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Commit 70596165 authored by Bin Liu's avatar Bin Liu Committed by Sasha Levin
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usb: musb: cppi41: improve rx channel abort routine 



[ Upstream commit cb83df77f3ec151d68a1b6be957207e6fc7b7f50 ]

1. set AUTOREQ to NONE at the beginning of teardown;

2. add delay for dma pipeline to drain;

3. Do not set USB_TDOWN bit for RX teardown.

  The CPPI hw has an issue that when tearing down a RX channel, if
  another RX channel is receiving data, the CPPI will lockup.

  To workaround the issue, do not set the CPPI TD bit. The steps before
  this point ensures the CPPI channel will be torn down properly.

Signed-off-by: default avatarBin Liu <b-liu@ti.com>
Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
parent 44b87b60

drivers/usb/musb/musb_cppi41.c

+9 −3
Original line number Diff line number Diff line
@@ -541,10 +541,15 @@ static int cppi41_dma_channel_abort(struct dma_channel *channel) 
		csr &= ~MUSB_TXCSR_DMAENAB;

		musb_writew(epio, MUSB_TXCSR, csr);

	} else {

		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);



		csr = musb_readw(epio, MUSB_RXCSR);

		csr &= ~(MUSB_RXCSR_H_REQPKT | MUSB_RXCSR_DMAENAB);

		musb_writew(epio, MUSB_RXCSR, csr);



		/* wait to drain cppi dma pipe line */

		udelay(50);



		csr = musb_readw(epio, MUSB_RXCSR);

		if (csr & MUSB_RXCSR_RXPKTRDY) {

			csr |= MUSB_RXCSR_FLUSHFIFO;
@@ -558,13 +563,14 @@ static int cppi41_dma_channel_abort(struct dma_channel *channel) 
		tdbit <<= 16;



	do {

		if (is_tx)

			musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);

		ret = dmaengine_terminate_all(cppi41_channel->dc);

	} while (ret == -EAGAIN);



	if (is_tx) {

		musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);



	if (is_tx) {

		csr = musb_readw(epio, MUSB_TXCSR);

		if (csr & MUSB_TXCSR_TXPKTRDY) {

			csr |= MUSB_TXCSR_FLUSHFIFO;