| Message ID | 1373957732-16638-3-git-send-email-b32955@freescale.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Jul 16, 2013 at 02:55:31PM +0800, Huang Shijie wrote: > The original DMA support works only when RTS/CTS is enabled. What is original here? > But after several patches, DMA support has lost this limit. This is still misleading. > This patch adds an optional property for the UART DT node > which indicates the UART has RTS and CTS lines. > > This patch also adds a macro MXS_AUART_RTSCTS, and uses it to check > RTS/CTS before we enable the DMA for the UART. I still think this should go to stable. The options are: a) also take patch 1 into stable b) apply this patch without patch 1 I don't know if option a) is OK, b) is probably preferable. And as Greg has much to do anyhow, better move this patch first. (Otherwise he will probably only say: That patch doesn't apply, please help.) > Signed-off-by: Huang Shijie <b32955@freescale.com> > --- > .../bindings/tty/serial/fsl-mxs-auart.txt | 4 ++++ > drivers/tty/serial/mxs-auart.c | 5 ++++- > 2 files changed, 8 insertions(+), 1 deletions(-) > > diff --git a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt > index 2c00ec6..59a40f1 100644 > --- a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt > +++ b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt > @@ -10,6 +10,10 @@ Required properties: > Refer to dma.txt and fsl-mxs-dma.txt for details. > - dma-names: "rx" for RX channel, "tx" for TX channel. > > +Optional properties: > +- fsl,uart-has-rtscts : Indicate the UART has RTS and CTS lines, > + it also means you enable the DMA support for this UART. > + > Example: > auart0: serial@8006a000 { > compatible = "fsl,imx28-auart", "fsl,imx23-auart"; > diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c > index 465ef0b..27532fd 100644 > --- a/drivers/tty/serial/mxs-auart.c > +++ b/drivers/tty/serial/mxs-auart.c > @@ -134,6 +134,7 @@ enum mxs_auart_type { > struct mxs_auart_port { > struct uart_port port; > > +#define MXS_AUART_RTSCTS 1 > #define MXS_AUART_DMA_ENABLED 0x2 > #define MXS_AUART_DMA_TX_SYNC 2 /* bit 2 */ > #define MXS_AUART_DMA_RX_READY 3 /* bit 3 */ > @@ -639,7 +640,7 @@ static void mxs_auart_settermios(struct uart_port *u, > * we can only implement the DMA support for auart > * in mx28. > */ > - if (is_imx28_auart(s)) { > + if (is_imx28_auart(s) && (s->flags & MXS_AUART_RTSCTS)) { I thought you wanted to add a comment here. Without knowing the details if (RTSCTS) enable_dma(); looks strange. Best regards Uwe
? 2013?07?16? 17:54, Uwe Kleine-König ??: > On Tue, Jul 16, 2013 at 02:55:31PM +0800, Huang Shijie wrote: >> The original DMA support works only when RTS/CTS is enabled. > What is original here? > i will add more information for this in the next version. >> But after several patches, DMA support has lost this limit. > This is still misleading. > >> This patch adds an optional property for the UART DT node >> which indicates the UART has RTS and CTS lines. >> >> This patch also adds a macro MXS_AUART_RTSCTS, and uses it to check >> RTS/CTS before we enable the DMA for the UART. > I still think this should go to stable. The options are: > > a) also take patch 1 into stable > b) apply this patch without patch 1 > > I don't know if option a) is OK, b) is probably preferable. And as Greg to Greg: I think a) is ok to me. what's your opinion? > has much to do anyhow, better move this patch first. (Otherwise he will > probably only say: That patch doesn't apply, please help.) > >> Signed-off-by: Huang Shijie<b32955@freescale.com> >> --- >> .../bindings/tty/serial/fsl-mxs-auart.txt | 4 ++++ >> drivers/tty/serial/mxs-auart.c | 5 ++++- >> 2 files changed, 8 insertions(+), 1 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt >> index 2c00ec6..59a40f1 100644 >> --- a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt >> +++ b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt >> @@ -10,6 +10,10 @@ Required properties: >> Refer to dma.txt and fsl-mxs-dma.txt for details. >> - dma-names: "rx" for RX channel, "tx" for TX channel. >> >> +Optional properties: >> +- fsl,uart-has-rtscts : Indicate the UART has RTS and CTS lines, >> + it also means you enable the DMA support for this UART. >> + >> Example: >> auart0: serial@8006a000 { >> compatible = "fsl,imx28-auart", "fsl,imx23-auart"; >> diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c >> index 465ef0b..27532fd 100644 >> --- a/drivers/tty/serial/mxs-auart.c >> +++ b/drivers/tty/serial/mxs-auart.c >> @@ -134,6 +134,7 @@ enum mxs_auart_type { >> struct mxs_auart_port { >> struct uart_port port; >> >> +#define MXS_AUART_RTSCTS 1 >> #define MXS_AUART_DMA_ENABLED 0x2 >> #define MXS_AUART_DMA_TX_SYNC 2 /* bit 2 */ >> #define MXS_AUART_DMA_RX_READY 3 /* bit 3 */ >> @@ -639,7 +640,7 @@ static void mxs_auart_settermios(struct uart_port *u, >> * we can only implement the DMA support for auart >> * in mx28. >> */ >> - if (is_imx28_auart(s)) { >> + if (is_imx28_auart(s)&& (s->flags& MXS_AUART_RTSCTS)) { > I thought you wanted to add a comment here. Without knowing the details > > if (RTSCTS) > enable_dma(); > ok, no problem. thanks Huang Shijie
On Wed, Jul 17, 2013 at 03:33:22PM +0800, Huang Shijie wrote: > ? 2013?07?16? 17:54, Uwe Kleine-König ??: > >On Tue, Jul 16, 2013 at 02:55:31PM +0800, Huang Shijie wrote: > >>The original DMA support works only when RTS/CTS is enabled. > >What is original here? > > > i will add more information for this in the next version. > >>But after several patches, DMA support has lost this limit. > >This is still misleading. > > > >>This patch adds an optional property for the UART DT node > >>which indicates the UART has RTS and CTS lines. > >> > >>This patch also adds a macro MXS_AUART_RTSCTS, and uses it to check > >>RTS/CTS before we enable the DMA for the UART. > >I still think this should go to stable. The options are: > > > > a) also take patch 1 into stable > > b) apply this patch without patch 1 > > > >I don't know if option a) is OK, b) is probably preferable. And as Greg > to Greg: > > I think a) is ok to me. what's your opinion? Please reorder them, making patch 2 first, and mark it for stable, then do patch 1, and the rest, so I don't have to take non-needed patches into the stable tree. thanks, greg k-h
diff --git a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt index 2c00ec6..59a40f1 100644 --- a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt +++ b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt @@ -10,6 +10,10 @@ Required properties: Refer to dma.txt and fsl-mxs-dma.txt for details. - dma-names: "rx" for RX channel, "tx" for TX channel. +Optional properties: +- fsl,uart-has-rtscts : Indicate the UART has RTS and CTS lines, + it also means you enable the DMA support for this UART. + Example: auart0: serial@8006a000 { compatible = "fsl,imx28-auart", "fsl,imx23-auart"; diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c index 465ef0b..27532fd 100644 --- a/drivers/tty/serial/mxs-auart.c +++ b/drivers/tty/serial/mxs-auart.c @@ -134,6 +134,7 @@ enum mxs_auart_type { struct mxs_auart_port { struct uart_port port; +#define MXS_AUART_RTSCTS 1 #define MXS_AUART_DMA_ENABLED 0x2 #define MXS_AUART_DMA_TX_SYNC 2 /* bit 2 */ #define MXS_AUART_DMA_RX_READY 3 /* bit 3 */ @@ -639,7 +640,7 @@ static void mxs_auart_settermios(struct uart_port *u, * we can only implement the DMA support for auart * in mx28. */ - if (is_imx28_auart(s)) { + if (is_imx28_auart(s) && (s->flags & MXS_AUART_RTSCTS)) { if (!mxs_auart_dma_init(s)) /* enable DMA tranfer */ ctrl2 |= AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE @@ -1001,6 +1002,8 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s, } s->port.line = ret; + if (of_get_property(np, "fsl,uart-has-rtscts", NULL)) + s->flags |= MXS_AUART_RTSCTS; return 0; }
The original DMA support works only when RTS/CTS is enabled. But after several patches, DMA support has lost this limit. This patch adds an optional property for the UART DT node which indicates the UART has RTS and CTS lines. This patch also adds a macro MXS_AUART_RTSCTS, and uses it to check RTS/CTS before we enable the DMA for the UART. Signed-off-by: Huang Shijie <b32955@freescale.com> --- .../bindings/tty/serial/fsl-mxs-auart.txt | 4 ++++ drivers/tty/serial/mxs-auart.c | 5 ++++- 2 files changed, 8 insertions(+), 1 deletions(-)