* Tero.Kristo@xxxxxxxxx <Tero.Kristo@xxxxxxxxx> [100203 23:59]: > > > >-----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. Yeah cool. Separate issue, but I wonder if we should also clear the the first rx character from the fifo to avoid corrupting the console. Only when the uart clocks are off and and we get a key press. Would be easy to do just do with one serial_read_reg(uart->p, UART_RX).. Tony > > -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
