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| author | Jon Hunter <jon-hunter@ti.com> | 2011-11-09 13:04:49 +0100 |
|---|---|---|
| committer | Kevin Hilman <khilman@ti.com> | 2011-12-15 01:05:24 +0100 |
| commit | a9e210e0b7a344c0e44aa6bf6888176bbc635c42 (patch) | |
| tree | e24466ff2fd9c2f10979d5fce32a870c451448ff /arch/arm/mach-omap2 | |
| parent | ARM: OMAP2+: UART: Allow UART parameters to be configured from board file. (diff) | |
| download | linux-a9e210e0b7a344c0e44aa6bf6888176bbc635c42.tar.xz linux-a9e210e0b7a344c0e44aa6bf6888176bbc635c42.zip | |
ARM: OMAP2+: UART: Make the RX_TIMEOUT for DMA configurable for each UART
When using DMA there are two timeouts defined. The first timeout,
rx_timeout, is really a polling rate in which software polls the
DMA status to see if the DMA has finished. This is necessary for
the RX side because we do not know how much data we will receive.
The secound timeout, RX_TIMEOUT, is a timeout after which the
DMA will be stopped if no more data is received. To make this
clearer, rename rx_timeout as rx_poll_rate and rename the
function serial_omap_rx_timeout() to serial_omap_rxdma_poll().
The OMAP-Serial driver defines an RX_TIMEOUT of 3 seconds that is
used to indicate when the DMA for UART can be stopped if no more
data is received. The value is a global definition that is applied
to all instances of the UART.
Each UART may be used for a different purpose and so the timeout
required may differ. Make this value configurable for each UART so
that this value can be optimised for power savings.
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> (for drivers/tty changes)
Signed-off-by: Kevin Hilman <khilman@ti.com>
Diffstat (limited to 'arch/arm/mach-omap2')
| -rw-r--r-- | arch/arm/mach-omap2/serial.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c index 5b1b36a45e9c..5dd928945033 100644 --- a/arch/arm/mach-omap2/serial.c +++ b/arch/arm/mach-omap2/serial.c @@ -64,13 +64,15 @@ struct omap_uart_state { static LIST_HEAD(uart_list); static u8 num_uarts; -#define DEFAULT_RXDMA_TIMEOUT 1 /* RX DMA polling rate (us) */ +#define DEFAULT_RXDMA_POLLRATE 1 /* RX DMA polling rate (us) */ #define DEFAULT_RXDMA_BUFSIZE 4096 /* RX DMA buffer size */ +#define DEFAULT_RXDMA_TIMEOUT (3 * HZ)/* RX DMA timeout (jiffies) */ static struct omap_uart_port_info omap_serial_default_info[] __initdata = { { .dma_enabled = false, .dma_rx_buf_size = DEFAULT_RXDMA_BUFSIZE, + .dma_rx_poll_rate = DEFAULT_RXDMA_POLLRATE, .dma_rx_timeout = DEFAULT_RXDMA_TIMEOUT, .autosuspend_timeout = DEFAULT_AUTOSUSPEND_DELAY, }, @@ -351,6 +353,7 @@ void __init omap_serial_init_port(struct omap_board_data *bdata, omap_up.enable_wakeup = omap_uart_enable_wakeup; omap_up.dma_rx_buf_size = info->dma_rx_buf_size; omap_up.dma_rx_timeout = info->dma_rx_timeout; + omap_up.dma_rx_poll_rate = info->dma_rx_poll_rate; omap_up.autosuspend_timeout = info->autosuspend_timeout; /* Enable the MDR1 Errata i202 for OMAP2430/3xxx/44xx */ |