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>
diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
index a740a6c..ea63b2bc 100644
--- a/arch/arm/plat-omap/include/plat/omap-serial.h
+++ b/arch/arm/plat-omap/include/plat/omap-serial.h
@@ -53,7 +53,6 @@
#define OMAP_UART_DMA_CH_FREE -1
-#define RX_TIMEOUT (3 * HZ)
#define OMAP_MAX_HSUART_PORTS 4
#define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA
@@ -69,6 +68,7 @@
unsigned int dma_rx_buf_size;
unsigned int dma_rx_timeout;
unsigned int autosuspend_timeout;
+ unsigned int dma_rx_poll_rate;
int (*get_context_loss_count)(struct device *);
void (*set_forceidle)(struct platform_device *);
@@ -98,6 +98,7 @@
/* timer to poll activity on rx dma */
struct timer_list rx_timer;
unsigned int rx_buf_size;
+ unsigned int rx_poll_rate;
unsigned int rx_timeout;
};