system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-11-05 18:23:50 +00:00
Code Issues Projects Releases Packages Wiki Activity

atmel_serial: avoid stopping pdc during transmission

Browse source 
I found a problem related to losing data during pdc transmission in
atmel_serial: connect ttyS1 with ttyS2 using a loopback cable, send 30
byte of packet from one to the other and waiting for 30 byte.  On the
other side just read and echo the data received.

We always call atmel_tx_dma() from the tasklet regardless of what interrupt
triggered it.

Signed-off-by: michael <trimarchi@gandalf.sssup.it>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Trimarchi 2008-04-02 13:04:41 -07:00 committed by Linus Torvalds
parent dd135ebbd2
commit ba0657ff05
1 changed files with 10 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

19
drivers/serial/atmel_serial.c
View file

@ -96,6 +96,7 @@
/* PDC registers */
#define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
#define UART_GET_TCR(port) __raw_readl((port)->membase + ATMEL_PDC_TCR)
#define UART_GET_PTSR(port) __raw_readl((port)->membase + ATMEL_PDC_PTSR)
#define UART_PUT_RPR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
@ -562,17 +563,22 @@ static void atmel_tx_dma(struct uart_port *port)
struct atmel_dma_buffer *pdc = &atmel_port->pdc_tx;
int count;
/* nothing left to transmit? */
if (UART_GET_TCR(port))
return;
xmit->tail += pdc->ofs;
xmit->tail &= UART_XMIT_SIZE - 1;
port->icount.tx += pdc->ofs;
pdc->ofs = 0;
if (!uart_circ_empty(xmit)) {
/* more to transmit - setup next transfer */
/* more to transmit - setup next transfer */
/* disable PDC transmit */
UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
/* disable PDC transmit */
UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
if (!uart_circ_empty(xmit)) {
dma_sync_single_for_device(port->dev,
pdc->dma_addr,
pdc->dma_size,
@ -586,11 +592,6 @@ static void atmel_tx_dma(struct uart_port *port)
/* re-enable PDC transmit and interrupts */
UART_PUT_PTCR(port, ATMEL_PDC_TXTEN);
UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE);
} else {
/* nothing left to transmit - disable the transmitter */
/* disable PDC transmit */
UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS);
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)