From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Subject: Re: OMAP1 realtime patch Date: Mon, 12 Feb 2007 21:34:18 +0100 Message-ID: <45D0CF4A.5000301@googlemail.com> References: <45C785A4.6080007@googlemail.com> <1170882015.11368.25.camel@vence.hilman.org> <45CB6775.7020500@googlemail.com> <45CF4BD1.6010109@googlemail.com> <1171308270.20717.32.camel@vence.hilman.org> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------050305000500090109060108" Return-path: In-Reply-To: <1171308270.20717.32.camel@vence.hilman.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-omap-open-source-bounces+gplao-linux-omap-open-source=gmane.org@linux.omap.com Errors-To: linux-omap-open-source-bounces+gplao-linux-omap-open-source=gmane.org@linux.omap.com To: Kevin Hilman Cc: linux-omap-open-source@linux.omap.com List-Id: linux-omap@vger.kernel.org This is a multi-part message in MIME format. --------------050305000500090109060108 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Kevin Hilman wrote: > On Sun, 2007-02-11 at 18:01 +0100, Dirk Behme wrote: > >>Dirk Behme wrote: >> >>>Kevin Hilman wrote: >>> >>> >>>>Here is a patch which leaves out the raw_spinlock conversions. It goes >>>>on the OMAP git tree on top of -rt5 (ignoring conflicts.) I've left out >>>>all the raw_spinlock conversions. This has been tested on an >>>>OMAP1623/H2 platform. >>> >>>Update of Kevins update. Tested on OSK. >>> >>>Changes: >>> >>>- Remove kernel/printk.c "+ zap_rt_locks();". It's already in -rt5. >>> >>>- Re-add HRTIMER conversion to ads7846.c >>> >>>With this patch I get Oops below after playing mp3 via NFS. Add >>>raw_spinlock_t to sound/arm/omap/omap-alsa-dma.c like in my original >>>patch doesn't seem to help. >> >>Re-adding raw_spinlock_t to omap-alsa.h helps against this Oops. > > > My guess the oops you sent is that you saw this crash when doing a > Ctrl-C or otherwise stopping the playback, correct? Nearly ;) Even without Ctrl-C this Oops happened. Simply waiting for mp3 to finish and coming back to prompt triggered it. Your patch fixes this. > This oops is triggered by the same thread trying to take the same > spinlock (now an rt_mutex under PREEMPT_RT.) The following patch > fixes the nested spinlocks, and removes the raw_spinlock. It applies > on top of your latest patch. Update to patch-2.6.20-rt5-omap3 in attachment. Changes: - Add Kevins fix for nested omap-alsa.c spinlocks and remove raw_spinlock workaround. Thanks! > On my OSK, I do notice however that using -rt (with and without this > fix) mp3 playback has some audible noise under PREEMPT_RT. Do you hear > this too? > Another data point... I only hear the noise when using mpg123 to play > an .mp3 file. If I use aplay to play a .wav file, I'm not hearing any > noise. I can even ping flood the target and audio plays without > problems. I use madplay MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al. to play mp3. I explicitly checked it again and don't think there is any noise. Maybe a mpg123 related issue? Far from it, I have the feeling that mp3 playback improves with -rt. In the past I had some random noise with my mp3 test song (nobody else seemed to have ;) ). With -rt I have the impression that it's better. Dirk --------------050305000500090109060108 Content-Type: text/plain; name="patch-2.6.20-rt5-omap3" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="patch-2.6.20-rt5-omap3" Index: linux-osk/arch/arm/mach-omap1/time.c =================================================================== --- linux-osk.orig/arch/arm/mach-omap1/time.c +++ linux-osk/arch/arm/mach-omap1/time.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include @@ -102,15 +103,33 @@ static inline unsigned long omap_mpu_tim return timer->read_tim; } -static inline void omap_mpu_timer_start(int nr, unsigned long load_val) +static inline void omap_mpu_set_autoreset(int nr) { volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr); + timer->cntl = timer->cntl | MPU_TIMER_AR; +} + +static inline void omap_mpu_remove_autoreset(int nr) +{ + volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr); + + timer->cntl = timer->cntl & ~MPU_TIMER_AR; +} + +static inline void omap_mpu_timer_start(int nr, unsigned long load_val, + int autoreset) +{ + volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr); + unsigned int timerflags = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST); + + if (autoreset) timerflags |= MPU_TIMER_AR; + timer->cntl = MPU_TIMER_CLOCK_ENABLE; udelay(1); timer->load_tim = load_val; udelay(1); - timer->cntl = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_AR | MPU_TIMER_ST); + timer->cntl = timerflags; } /* @@ -118,12 +137,42 @@ static inline void omap_mpu_timer_start( * MPU timer 1 ... count down to zero, interrupt, reload * --------------------------------------------------------------------------- */ +static int omap_mpu_set_next_event(unsigned long cycles, + struct clock_event_device *evt) +{ + omap_mpu_timer_start(0, cycles, 0); + return 0; +} + +static void omap_mpu_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + omap_mpu_set_autoreset(0); + break; + case CLOCK_EVT_MODE_ONESHOT: + omap_mpu_remove_autoreset(0); + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + break; + } +} + +static struct clock_event_device clockevent_mpu_timer1 = { + .name = "mpu_timer1", + .features = CLOCK_EVT_FEAT_PERIODIC, CLOCK_EVT_FEAT_ONESHOT, + .shift = 32, + .set_next_event = omap_mpu_set_next_event, + .set_mode = omap_mpu_set_mode, +}; + static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id) { - write_seqlock(&xtime_lock); - /* NOTE: no lost-tick detection/handling! */ - timer_tick(); - write_sequnlock(&xtime_lock); + struct clock_event_device *evt = &clockevent_mpu_timer1; + + evt->event_handler(evt); return IRQ_HANDLED; } @@ -139,7 +188,17 @@ static __init void omap_init_mpu_timer(u set_cyc2ns_scale(rate / 1000); setup_irq(INT_TIMER1, &omap_mpu_timer1_irq); - omap_mpu_timer_start(0, (rate / HZ) - 1); + omap_mpu_timer_start(0, (rate / HZ) - 1, 1); + + clockevent_mpu_timer1.mult = div_sc(rate, NSEC_PER_SEC, + clockevent_mpu_timer1.shift); + clockevent_mpu_timer1.max_delta_ns = + clockevent_delta2ns(-1, &clockevent_mpu_timer1); + clockevent_mpu_timer1.min_delta_ns = + clockevent_delta2ns(1, &clockevent_mpu_timer1); + + clockevent_mpu_timer1.cpumask = cpumask_of_cpu(0); + clockevents_register_device(&clockevent_mpu_timer1); } /* @@ -173,7 +232,7 @@ static struct clocksource clocksource_mp .read = mpu_read, .mask = CLOCKSOURCE_MASK(32), .shift = 24, - .is_continuous = 1, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static void __init omap_init_clocksource(unsigned long rate) @@ -185,7 +244,7 @@ static void __init omap_init_clocksource = clocksource_khz2mult(rate/1000, clocksource_mpu.shift); setup_irq(INT_TIMER2, &omap_mpu_timer2_irq); - omap_mpu_timer_start(1, ~0); + omap_mpu_timer_start(1, ~0, 1); if (clocksource_register(&clocksource_mpu)) printk(err, clocksource_mpu.name); Index: linux-osk/arch/arm/plat-omap/timer32k.c =================================================================== --- linux-osk.orig/arch/arm/plat-omap/timer32k.c +++ linux-osk/arch/arm/plat-omap/timer32k.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #include @@ -210,23 +211,10 @@ unsigned long long sched_clock(void) */ static inline irqreturn_t _omap_32k_timer_interrupt(int irq, void *dev_id) { - unsigned long now; - + struct clock_event_device *evt = &clockevent_32k_timer; omap_32k_timer_ack_irq(); - now = omap_32k_sync_timer_read(); - while ((signed long)(now - omap_32k_last_tick) - >= OMAP_32K_TICKS_PER_HZ) { - omap_32k_last_tick += OMAP_32K_TICKS_PER_HZ; - timer_tick(); - } - - /* Restart timer so we don't drift off due to modulo or dynamic tick. - * By default we program the next timer to be continuous to avoid - * latencies during high system load. During dynamic tick operation the - * continuous timer can be overridden from pm_idle to be longer. - */ - omap_32k_timer_start(omap_32k_last_tick + OMAP_32K_TICKS_PER_HZ - now); + evt->event_handler(evt); return IRQ_HANDLED; } Index: linux-osk/arch/arm/plat-omap/common.c =================================================================== --- linux-osk.orig/arch/arm/plat-omap/common.c +++ linux-osk/arch/arm/plat-omap/common.c @@ -212,7 +212,7 @@ static struct clocksource clocksource_32 .read = omap_32k_read, .mask = CLOCKSOURCE_MASK(32), .shift = 10, - .is_continuous = 1, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static int __init omap_init_clocksource_32k(void) Index: linux-osk/kernel/irq/manage.c =================================================================== --- linux-osk.orig/kernel/irq/manage.c +++ linux-osk/kernel/irq/manage.c @@ -593,6 +593,7 @@ static void thread_simple_irq(irq_desc_t unsigned int irq = desc - irq_desc; irqreturn_t action_ret; + restart: if (action && !desc->depth) { spin_unlock(&desc->lock); action_ret = handle_IRQ_event(irq, action); @@ -601,6 +602,19 @@ static void thread_simple_irq(irq_desc_t if (!noirqdebug) note_interrupt(irq, desc, action_ret); } + + /* + * Some boards will disable an interrupt when it + * sets IRQ_PENDING . So we have to remove the flag + * and re-enable to handle it. + */ + if (desc->status & IRQ_PENDING) { + desc->status &= ~IRQ_PENDING; + if (desc->chip) + desc->chip->enable(irq); + goto restart; + } + desc->status &= ~IRQ_INPROGRESS; } Index: linux-osk/drivers/input/touchscreen/ads7846.c =================================================================== --- linux-osk.orig/drivers/input/touchscreen/ads7846.c +++ linux-osk/drivers/input/touchscreen/ads7846.c @@ -454,7 +454,7 @@ static void ads7846_rx(void *ads) ts->spi->dev.bus_id, ts->tc.ignore, Rt); #endif hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), - HRTIMER_REL); + HRTIMER_MODE_REL); return; } @@ -473,7 +473,8 @@ static void ads7846_rx(void *ads) ads7846_sync_events(ts); } - hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), HRTIMER_REL); + hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), + HRTIMER_MODE_REL); } static int ads7846_debounce(void *ads, int data_idx, int *val) @@ -558,7 +559,7 @@ static void ads7846_rx_val(void *ads) status); } -static int ads7846_timer(struct hrtimer *handle) +static enum hrtimer_restart ads7846_timer(struct hrtimer *handle) { struct ads7846 *ts = container_of(handle, struct ads7846, timer); int status = 0; @@ -609,7 +610,7 @@ static irqreturn_t ads7846_irq(int irq, disable_irq(ts->spi->irq); ts->pending = 1; hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY), - HRTIMER_REL); + HRTIMER_MODE_REL); } } spin_unlock_irqrestore(&ts->lock, flags); @@ -747,7 +748,7 @@ static int __devinit ads7846_probe(struc ts->input = input_dev; ts->hwmon = hwmon; - hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_REL); + hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); ts->timer.function = ads7846_timer; spin_lock_init(&ts->lock); Index: linux-osk/sound/arm/omap/omap-alsa.c =================================================================== --- linux-osk.orig/sound/arm/omap/omap-alsa.c +++ linux-osk/sound/arm/omap/omap-alsa.c @@ -167,7 +167,6 @@ static void audio_stop_dma(struct audio_ unsigned long flags; ADEBUG(); - spin_lock_irqsave(&s->dma_lock, flags); s->active = 0; s->period = 0; s->periods = 0; @@ -176,8 +175,6 @@ static void audio_stop_dma(struct audio_ omap_stop_alsa_sound_dma(s); omap_clear_alsa_sound_dma(s); - - spin_unlock_irqrestore(&s->dma_lock, flags); } /* --------------050305000500090109060108 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline --------------050305000500090109060108--