* [RESEND PATCH] 8250_core: Fix unwanted TX chars write
@ 2014-04-24 9:38 Loic Poulain
2014-04-24 10:24 ` Heikki Krogerus
0 siblings, 1 reply; 2+ messages in thread
From: Loic Poulain @ 2014-04-24 9:38 UTC (permalink / raw)
To: gregkh, heikki.krogerus; +Cc: linux-serial, Loic Poulain
On transmit-hold-register empty, serial8250_tx_chars
should be called only if we don't use DMA.
DMA has its own tx cycle.
Signed-off-by: Loic Poulain <loic.poulain@intel.com>
---
resend: just remove email footer disclaimer.
drivers/tty/serial/8250/8250_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 81f909c..0e1bf88 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1520,7 +1520,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
status = serial8250_rx_chars(up, status);
}
serial8250_modem_status(up);
- if (status & UART_LSR_THRE)
+ if (!up->dma && (status & UART_LSR_THRE))
serial8250_tx_chars(up);
spin_unlock_irqrestore(&port->lock, flags);
--
1.8.3.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [RESEND PATCH] 8250_core: Fix unwanted TX chars write
2014-04-24 9:38 [RESEND PATCH] 8250_core: Fix unwanted TX chars write Loic Poulain
@ 2014-04-24 10:24 ` Heikki Krogerus
0 siblings, 0 replies; 2+ messages in thread
From: Heikki Krogerus @ 2014-04-24 10:24 UTC (permalink / raw)
To: Loic Poulain; +Cc: gregkh, linux-serial
On Thu, Apr 24, 2014 at 11:38:56AM +0200, Loic Poulain wrote:
> On transmit-hold-register empty, serial8250_tx_chars
> should be called only if we don't use DMA.
> DMA has its own tx cycle.
>
> Signed-off-by: Loic Poulain <loic.poulain@intel.com>
This should also go to stable tree.
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Thanks,
--
heikki
^ permalink raw reply [flat|nested] 2+ messages in thread
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