diff options
| author | Dirk Behme <dirk.behme@de.bosch.com> | 2014-12-09 12:11:31 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-10 01:23:07 +0300 |
| commit | a2c718ce6a61f759fc47d632bcc3d8cf6b244581 (patch) | |
| tree | b1e4215e429d35b9ab456d2805873a055b4eb897 /drivers/tty/serial/imx.c | |
| parent | 0bbc9b81c1638f6e75c8ed423b5e6ae1a2035d79 (diff) | |
| download | linux-a2c718ce6a61f759fc47d632bcc3d8cf6b244581.tar.xz | |
serial: imx: disable TDMAEN in imx_flush_buffer()
Terminating the DMA, make sure the interrupt is disabled, too.
This fixes random kernel Oops due to dma_tx_call() called for
invalid transmissions.
If we disable the TDMAEN, make sure it's enabled again if a TX
DMA is started.
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/imx.c')
| -rw-r--r-- | drivers/tty/serial/imx.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 0e64f18f8c42..d097169e85d1 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -502,11 +502,16 @@ static void dma_tx_callback(void *data) struct scatterlist *sgl = &sport->tx_sgl[0]; struct circ_buf *xmit = &sport->port.state->xmit; unsigned long flags; + unsigned long temp; spin_lock_irqsave(&sport->port.lock, flags); dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); + temp = readl(sport->port.membase + UCR1); + temp &= ~UCR1_TDMAEN; + writel(temp, sport->port.membase + UCR1); + /* update the stat */ xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1); sport->port.icount.tx += sport->tx_bytes; @@ -539,6 +544,7 @@ static void imx_dma_tx(struct imx_port *sport) struct dma_async_tx_descriptor *desc; struct dma_chan *chan = sport->dma_chan_tx; struct device *dev = sport->port.dev; + unsigned long temp; int ret; if (sport->dma_is_txing) @@ -575,6 +581,11 @@ static void imx_dma_tx(struct imx_port *sport) dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n", uart_circ_chars_pending(xmit)); + + temp = readl(sport->port.membase + UCR1); + temp |= UCR1_TDMAEN; + writel(temp, sport->port.membase + UCR1); + /* fire it */ sport->dma_is_txing = 1; dmaengine_submit(desc); @@ -1258,6 +1269,7 @@ static void imx_flush_buffer(struct uart_port *port) { struct imx_port *sport = (struct imx_port *)port; struct scatterlist *sgl = &sport->tx_sgl[0]; + unsigned long temp; if (!sport->dma_chan_tx) return; @@ -1267,6 +1279,9 @@ static void imx_flush_buffer(struct uart_port *port) if (sport->dma_is_txing) { dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); + temp = readl(sport->port.membase + UCR1); + temp &= ~UCR1_TDMAEN; + writel(temp, sport->port.membase + UCR1); sport->dma_is_txing = false; } } |