| Message ID | 1464389648-4820-1-git-send-email-alexandre.belloni@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Le 28/05/2016 00:54, Alexandre Belloni a écrit : > When using DMA, half duplex doesn't work properly because rx is not stopped > before starting tx. Ensure we call atmel_stop_rx() in the DMA case. > > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> We can also add: Cc: <stable@vger.kernel.org> # v4.3+ Thanks Alexandre! > --- > drivers/tty/serial/atmel_serial.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > index 954941dd8124..f9c798cba83f 100644 > --- a/drivers/tty/serial/atmel_serial.c > +++ b/drivers/tty/serial/atmel_serial.c > @@ -482,19 +482,21 @@ static void atmel_start_tx(struct uart_port *port) > { > struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > - if (atmel_use_pdc_tx(port)) { > - if (atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN) > - /* The transmitter is already running. Yes, we > - really need this.*/ > - return; > + if (atmel_use_pdc_tx(port) && (atmel_uart_readl(port, ATMEL_PDC_PTSR) > + & ATMEL_PDC_TXTEN)) > + /* The transmitter is already running. Yes, we > + really need this.*/ > + return; > > + if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port)) > if ((port->rs485.flags & SER_RS485_ENABLED) && > !(port->rs485.flags & SER_RS485_RX_DURING_TX)) > atmel_stop_rx(port); > > + if (atmel_use_pdc_tx(port)) > /* re-enable PDC transmit */ > atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN); > - } > + > /* Enable interrupts */ > atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); > } >
Le 02/06/2016 12:41, Nicolas Ferre a écrit : > Le 28/05/2016 00:54, Alexandre Belloni a écrit : >> When using DMA, half duplex doesn't work properly because rx is not stopped >> before starting tx. Ensure we call atmel_stop_rx() in the DMA case. >> >> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > > Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> > > We can also add: > Cc: <stable@vger.kernel.org> # v4.3+ > > > Thanks Alexandre! Greg, It's not a regression but a good fix for this rs485 mode. So I suspect it can still be queued for 4.7-rc... (aka: gentle ping). Bye, >> --- >> drivers/tty/serial/atmel_serial.c | 14 ++++++++------ >> 1 file changed, 8 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c >> index 954941dd8124..f9c798cba83f 100644 >> --- a/drivers/tty/serial/atmel_serial.c >> +++ b/drivers/tty/serial/atmel_serial.c >> @@ -482,19 +482,21 @@ static void atmel_start_tx(struct uart_port *port) >> { >> struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); >> >> - if (atmel_use_pdc_tx(port)) { >> - if (atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN) >> - /* The transmitter is already running. Yes, we >> - really need this.*/ >> - return; >> + if (atmel_use_pdc_tx(port) && (atmel_uart_readl(port, ATMEL_PDC_PTSR) >> + & ATMEL_PDC_TXTEN)) >> + /* The transmitter is already running. Yes, we >> + really need this.*/ >> + return; >> >> + if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port)) >> if ((port->rs485.flags & SER_RS485_ENABLED) && >> !(port->rs485.flags & SER_RS485_RX_DURING_TX)) >> atmel_stop_rx(port); >> >> + if (atmel_use_pdc_tx(port)) >> /* re-enable PDC transmit */ >> atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN); >> - } >> + >> /* Enable interrupts */ >> atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); >> } >> > >
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 954941dd8124..f9c798cba83f 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -482,19 +482,21 @@ static void atmel_start_tx(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (atmel_use_pdc_tx(port)) { - if (atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN) - /* The transmitter is already running. Yes, we - really need this.*/ - return; + if (atmel_use_pdc_tx(port) && (atmel_uart_readl(port, ATMEL_PDC_PTSR) + & ATMEL_PDC_TXTEN)) + /* The transmitter is already running. Yes, we + really need this.*/ + return; + if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port)) if ((port->rs485.flags & SER_RS485_ENABLED) && !(port->rs485.flags & SER_RS485_RX_DURING_TX)) atmel_stop_rx(port); + if (atmel_use_pdc_tx(port)) /* re-enable PDC transmit */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN); - } + /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); }
When using DMA, half duplex doesn't work properly because rx is not stopped before starting tx. Ensure we call atmel_stop_rx() in the DMA case. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> --- drivers/tty/serial/atmel_serial.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)