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| author | Aaron Brice <aaron.brice@datasoft.com> | 2016-10-06 15:13:04 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-10-27 16:41:56 +0200 |
| commit | d704b2d32c39c256dea659e142a31b875a13c63b (patch) | |
| tree | e104411d0b6a56d00ed2f6a8b274ce95292e5d66 /drivers/tty | |
| parent | f00a7c57569db04633818bc5e0c0e35d62733b02 (diff) | |
| download | linux-d704b2d32c39c256dea659e142a31b875a13c63b.tar.gz linux-d704b2d32c39c256dea659e142a31b875a13c63b.tar.bz2 linux-d704b2d32c39c256dea659e142a31b875a13c63b.zip | |
tty: serial: fsl_lpuart: Fix Tx DMA edge case
In the case where head == 0 on the circular buffer, there should be one
DMA buffer, not two. The second zero-length buffer would break the
lpuart driver, transfer would never complete.
Signed-off-by: Aaron Brice <aaron.brice@datasoft.com>
Acked-by: Stefan Agner <stefan@agner.ch>
Tested-by: Stefan Agner <stefan@agner.ch>
Tested-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/fsl_lpuart.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index de9d5107c00a..76103f2c4a80 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -328,7 +328,7 @@ static void lpuart_dma_tx(struct lpuart_port *sport) sport->dma_tx_bytes = uart_circ_chars_pending(xmit); - if (xmit->tail < xmit->head) { + if (xmit->tail < xmit->head || xmit->head == 0) { sport->dma_tx_nents = 1; sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes); } else { @@ -359,7 +359,6 @@ static void lpuart_dma_tx(struct lpuart_port *sport) sport->dma_tx_in_progress = true; sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc); dma_async_issue_pending(sport->dma_tx_chan); - } static void lpuart_dma_tx_complete(void *arg) |