Grr, ktime_get() is not accessible during suspend, and thus this patch causes a WARN during wakeup from suspend. I'll convert the patch to use getrawmonotonic() instead, sending out a refreshed one soon.
>-----Original Message----- >From: linux-omap-ow...@vger.kernel.org >[mailto:linux-omap-ow...@vger.kernel.org] On Behalf Of Kristo >Tero (Nokia-D/Tampere) >Sent: 12 February, 2010 20:23 >To: linux-omap@vger.kernel.org >Subject: [PATCHv4] OMAP3: Serial: Improved sleep logic > >From: Tero Kristo <tero.kri...@nokia.com> > >This patch contains following improvements: >- Only RX interrupt will now kick the sleep prevent timer >- TX fifo status is checked before disabling clocks, this will prevent > on-going transmission to be cut >- Smartidle is now enabled/disabled only while switching >clocks, as having > smartidle enabled while RX/TX prevents any wakeups from being > received from UART module >- Sleep prevent timer is changed to use ktime_get() instead of >a jiffy timer > as jiffy timers are not valid within idle loop (tick >scheduler is stopped) >- Added RX ignore timer for ignoring the first character >received during > first millisecond of wakeup, this prevents garbage character >to be receive > in low sleep states > >Signed-off-by: Tero Kristo <tero.kri...@nokia.com> >--- > arch/arm/mach-omap2/serial.c | 79 >+++++++++++++++++++++++++++-------------- > 1 files changed, 52 insertions(+), 27 deletions(-) > >diff --git a/arch/arm/mach-omap2/serial.c >b/arch/arm/mach-omap2/serial.c >index 5f3035e..4be9ace 100644 >--- a/arch/arm/mach-omap2/serial.c >+++ b/arch/arm/mach-omap2/serial.c >@@ -29,6 +29,8 @@ > #include <plat/clock.h> > #include <plat/control.h> > >+#include <asm/div64.h> >+ > #include "prm.h" > #include "pm.h" > #include "prm-regbits-34xx.h" >@@ -42,13 +44,14 @@ > * disabled via sysfs. This also causes that any deeper omap >sleep states are > * blocked. > */ >-#define DEFAULT_TIMEOUT 0 >+#define DEFAULT_TIMEOUT (0LL * NSEC_PER_SEC) > > struct omap_uart_state { > int num; > int can_sleep; >- struct timer_list timer; >- u32 timeout; >+ ktime_t expire_time; >+ ktime_t garbage_time; >+ u64 timeout; > > void __iomem *wk_st; > void __iomem *wk_en; >@@ -243,6 +246,9 @@ static inline void >omap_uart_save_context(struct omap_uart_state *uart) {} > static inline void omap_uart_restore_context(struct >omap_uart_state *uart) {} > #endif /* CONFIG_PM && CONFIG_ARCH_OMAP3 */ > >+static void omap_uart_smart_idle_enable(struct omap_uart_state *uart, >+ int enable); >+ > static inline void omap_uart_enable_clocks(struct >omap_uart_state *uart) > { > if (uart->clocked) >@@ -250,8 +256,12 @@ static inline void >omap_uart_enable_clocks(struct omap_uart_state *uart) > > clk_enable(uart->ick); > clk_enable(uart->fck); >+ omap_uart_smart_idle_enable(uart, 0); > uart->clocked = 1; > omap_uart_restore_context(uart); >+ >+ /* Set up garbage timer to ignore RX during first 1ms */ >+ uart->garbage_time = ktime_add_ns(ktime_get(), NSEC_PER_MSEC); > } > > #ifdef CONFIG_PM >@@ -263,6 +273,7 @@ static inline void >omap_uart_disable_clocks(struct omap_uart_state *uart) > > omap_uart_save_context(uart); > uart->clocked = 0; >+ omap_uart_smart_idle_enable(uart, 1); > clk_disable(uart->ick); > clk_disable(uart->fck); > } >@@ -320,12 +331,9 @@ static void omap_uart_block_sleep(struct >omap_uart_state *uart) > { > omap_uart_enable_clocks(uart); > >- omap_uart_smart_idle_enable(uart, 0); > uart->can_sleep = 0; > if (uart->timeout) >- mod_timer(&uart->timer, jiffies + uart->timeout); >- else >- del_timer(&uart->timer); >+ uart->expire_time = ktime_add_ns(ktime_get(), >uart->timeout); > } > > static void omap_uart_allow_sleep(struct omap_uart_state *uart) >@@ -338,16 +346,7 @@ static void omap_uart_allow_sleep(struct >omap_uart_state *uart) > if (!uart->clocked) > return; > >- omap_uart_smart_idle_enable(uart, 1); > uart->can_sleep = 1; >- del_timer(&uart->timer); >-} >- >-static void omap_uart_idle_timer(unsigned long data) >-{ >- struct omap_uart_state *uart = (struct omap_uart_state *)data; >- >- omap_uart_allow_sleep(uart); > } > > void omap_uart_prepare_idle(int num) >@@ -355,8 +354,14 @@ void omap_uart_prepare_idle(int num) > struct omap_uart_state *uart; > > list_for_each_entry(uart, &uart_list, node) { >+ if (num == uart->num && !uart->can_sleep && >uart->timeout) >+ if (ktime_get().tv64 > uart->expire_time.tv64) >+ uart->can_sleep = 1; >+ > 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); > return; > } > } >@@ -404,6 +409,10 @@ int omap_uart_can_sleep(void) > if (!uart->clocked) > continue; > >+ if (!uart->can_sleep && uart->timeout && >+ ktime_get().tv64 > uart->expire_time.tv64) >+ uart->can_sleep = 1; >+ > if (!uart->can_sleep) { > can_sleep = 0; > continue; >@@ -428,10 +437,22 @@ 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; >+ int ret = IRQ_NONE; > >- 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 (uart->garbage_time.tv64 && >+ ktime_get().tv64 < uart->garbage_time.tv64) { >+ serial_read_reg(uart->p, UART_RX); >+ uart->garbage_time.tv64 = 0; >+ ret = IRQ_HANDLED; >+ } >+ } > >- return IRQ_NONE; >+ return ret; > } > > static void omap_uart_idle_init(struct omap_uart_state *uart) >@@ -441,10 +462,8 @@ static void omap_uart_idle_init(struct >omap_uart_state *uart) > > uart->can_sleep = 0; > uart->timeout = DEFAULT_TIMEOUT; >- setup_timer(&uart->timer, omap_uart_idle_timer, >- (unsigned long) uart); > if (uart->timeout) >- mod_timer(&uart->timer, jiffies + uart->timeout); >+ uart->expire_time = ktime_add_ns(ktime_get(), >uart->timeout); > omap_uart_smart_idle_enable(uart, 0); > > if (cpu_is_omap34xx()) { >@@ -527,8 +546,12 @@ static ssize_t sleep_timeout_show(struct >device *dev, > struct platform_device, dev); > struct omap_uart_state *uart = container_of(pdev, > struct omap_uart_state, pdev); >+ u64 val; >+ >+ val = uart->timeout; > >- return sprintf(buf, "%u\n", uart->timeout / HZ); >+ do_div(val, NSEC_PER_SEC); >+ return sprintf(buf, "%llu\n", val); > } > > static ssize_t sleep_timeout_store(struct device *dev, >@@ -546,10 +569,12 @@ static ssize_t >sleep_timeout_store(struct device *dev, > return -EINVAL; > } > >- uart->timeout = value * HZ; >- if (uart->timeout) >- mod_timer(&uart->timer, jiffies + uart->timeout); >- else >+ uart->timeout = (u64)value * NSEC_PER_SEC; >+ if (uart->timeout) { >+ uart->expire_time = ktime_get(); >+ uart->expire_time = >+ ktime_add_ns(uart->expire_time, uart->timeout); >+ } else > /* A zero value means disable timeout feature */ > omap_uart_block_sleep(uart); > >-- >1.5.4.3 > >-- >To unsubscribe from this list: send the line "unsubscribe >linux-omap" in >the body of a message to majord...@vger.kernel.org >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 majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
