>-----Original Message----- >From: ext Tony Lindgren [mailto:tony@xxxxxxxxxxx] >Sent: 03 February, 2010 19:50 >To: Kristo Tero (Nokia-D/Tampere) >Cc: linux-omap@xxxxxxxxxxxxxxx >Subject: Re: [PATCH] OMAP3: Serial: Improved sleep logic > >* Tero Kristo <tero.kristo@xxxxxxxxx> [100202 01:38]: >> From: Tero Kristo <tero.kristo@xxxxxxxxx> >> >> Only RX interrupt will now kick the sleep prevent timer. In >addition, TX >> fifo status is checked before disabling clocks, this will >prevent occasional >> garbage being printed on serial line. Smartidle is also >disabled while >> entering idle if we have data in the transmit buffer, >because having this >> enabled will prevent wakeups from the TX interrupt, and this causes >> pauses while sending large blocks of data. > >Sounds this is for 2.6.34 merge window and does not contain anything >that needs to be fixed for 2.6.33. Yeah, this only fixes a couple of annoying issues, but nothing fatal. Also improves power efficiency in some cases which is a nice to have feature, and basically eases the development of PM code as the UART does not block the system from sleeping always. -Tero > >Regards, > >Tony > > >> Signed-off-by: Tero Kristo <tero.kristo@xxxxxxxxx> >> --- >> arch/arm/mach-omap2/serial.c | 19 +++++++++++++++---- >> 1 files changed, 15 insertions(+), 4 deletions(-) >> >> diff --git a/arch/arm/mach-omap2/serial.c >b/arch/arm/mach-omap2/serial.c >> index 777e802..e11dfe9 100644 >> --- a/arch/arm/mach-omap2/serial.c >> +++ b/arch/arm/mach-omap2/serial.c >> @@ -317,7 +317,8 @@ static void omap_uart_allow_sleep(struct >omap_uart_state *uart) >> if (!uart->clocked) >> return; >> >> - omap_uart_smart_idle_enable(uart, 1); >> + if (serial_read_reg(uart->p, UART_LSR) & UART_LSR_TEMT) >> + omap_uart_smart_idle_enable(uart, 1); >> uart->can_sleep = 1; >> del_timer(&uart->timer); >> } >> @@ -335,7 +336,11 @@ void omap_uart_prepare_idle(int num) >> >> list_for_each_entry(uart, &uart_list, node) { >> if (num == uart->num && uart->can_sleep) { >> - omap_uart_disable_clocks(uart); >> + if (serial_read_reg(uart->p, UART_LSR) & >> + UART_LSR_TEMT) >> + omap_uart_disable_clocks(uart); >> + else >> + omap_uart_smart_idle_enable(uart, 0); >> return; >> } >> } >> @@ -407,8 +412,14 @@ int omap_uart_can_sleep(void) >> static irqreturn_t omap_uart_interrupt(int irq, void *dev_id) >> { >> struct omap_uart_state *uart = dev_id; >> + u8 lsr; >> >> - omap_uart_block_sleep(uart); >> + lsr = serial_read_reg(uart->p, UART_LSR); >> + /* Check for receive interrupt */ >> + if (lsr & UART_LSR_DR) >> + omap_uart_block_sleep(uart); >> + if (lsr & UART_LSR_TEMT && uart->can_sleep) >> + omap_uart_smart_idle_enable(uart, 1); >> >> return IRQ_NONE; >> } >> -- >> 1.5.4.3 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe >linux-omap" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >-- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
