diff options
| author | Feng Tang <feng.tang@intel.com> | 2011-02-22 15:28:10 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-02-22 15:49:00 -0800 |
| commit | 085a4f758f0cf95e1865b63892bf4304a149f0ca (patch) | |
| tree | e2649fbbf7ccc74b506f9415f740730d503e97d2 | |
| parent | 10e82f6ce76351425644bccc56f8e2c2ad596ce6 (diff) | |
| download | linux-085a4f758f0cf95e1865b63892bf4304a149f0ca.tar.bz2 | |
serial: mfd: remove the TX full-empty interrupts workaround
In A0 stepping, TX half-empty interrupt is not working, so have to
use the full-empty interrupts whose performance will be 15% lower.
Now re-enable the half-empty interrrupt after it is enabled in
silicon.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/tty/serial/mfd.c | 26 |
1 files changed, 5 insertions, 21 deletions
diff --git a/drivers/tty/serial/mfd.c b/drivers/tty/serial/mfd.c index 776777462937..53ff6af16273 100644 --- a/drivers/tty/serial/mfd.c +++ b/drivers/tty/serial/mfd.c @@ -16,9 +16,7 @@ * 2/3 chan to port 1, 4/5 chan to port 3. Even number chans * are used for RX, odd chans for TX * - * 2. In A0 stepping, UART will not support TX half empty flag - * - * 3. The RI/DSR/DCD/DTR are not pinned out, DCD & DSR are always + * 2. The RI/DSR/DCD/DTR are not pinned out, DCD & DSR are always * asserted, only when the HW is reset the DDCD and DDSR will * be triggered */ @@ -41,8 +39,6 @@ #include <linux/io.h> #include <linux/debugfs.h> -#define MFD_HSU_A0_STEPPING 1 - #define HSU_DMA_BUF_SIZE 2048 #define chan_readl(chan, offset) readl(chan->reg + offset) @@ -543,16 +539,9 @@ static void transmit_chars(struct uart_hsu_port *up) return; } -#ifndef MFD_HSU_A0_STEPPING + /* The IRQ is for TX FIFO half-empty */ count = up->port.fifosize / 2; -#else - /* - * A0 only supports fully empty IRQ, and the first char written - * into it won't clear the EMPT bit, so we may need be cautious - * by useing a shorter buffer - */ - count = up->port.fifosize - 4; -#endif + do { serial_out(up, UART_TX, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); @@ -761,9 +750,8 @@ static void serial_hsu_break_ctl(struct uart_port *port, int break_state) /* * What special to do: * 1. chose the 64B fifo mode - * 2. make sure not to select half empty mode for A0 stepping - * 3. start dma or pio depends on configuration - * 4. we only allocate dma memory when needed + * 2. start dma or pio depends on configuration + * 3. we only allocate dma memory when needed */ static int serial_hsu_startup(struct uart_port *port) { @@ -967,10 +955,6 @@ serial_hsu_set_termios(struct uart_port *port, struct ktermios *termios, fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_32B; fcr |= UART_FCR_HSU_64B_FIFO; -#ifdef MFD_HSU_A0_STEPPING - /* A0 doesn't support half empty IRQ */ - fcr |= UART_FCR_FULL_EMPT_TXI; -#endif /* * Ok, we're now changing the port state. Do it with |