From f57e1abd1bb297994c7398478b4c37e628095243 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Fri, 18 Aug 2006 15:32:10 +0100 Subject: [PATCH] [ARM] 3753/1: S3C24XX: DMA fixes Patch from Ben Dooks A number of small issues with the S3C24XX DMA have cropped up, which this patch fixes. These are: - check wether we can load another buff in start - update state handling in s3c2410_dma_lastxfer - only reload in irq if channel is not idle - more informative timeout errors (add source) - do not call request_irq() with irqs locked - added waitforstop function The patch also adds a S3C2410_DMAOP_STARTED for the occasions when the driver wants to ensure that the DMA system load state is resynced after loading. Signed-off-by: Ben Dooks Signed-off-by: Russell King --- arch/arm/mach-s3c2410/dma.c | 163 ++++++++++++++++++++++++++++++++----- include/asm-arm/arch-s3c2410/dma.h | 1 + 2 files changed, 145 insertions(+), 19 deletions(-) diff --git a/arch/arm/mach-s3c2410/dma.c b/arch/arm/mach-s3c2410/dma.c index 094cc52..2585545 100644 --- a/arch/arm/mach-s3c2410/dma.c +++ b/arch/arm/mach-s3c2410/dma.c @@ -112,7 +112,7 @@ dmadbg_capture(s3c2410_dma_chan_t *chan, struct s3c2410_dma_regstate *regs) } static void -dmadbg_showregs(const char *fname, int line, s3c2410_dma_chan_t *chan, +dmadbg_dumpregs(const char *fname, int line, s3c2410_dma_chan_t *chan, struct s3c2410_dma_regstate *regs) { printk(KERN_DEBUG "dma%d: %s:%d: DCSRC=%08lx, DISRC=%08lx, DSTAT=%08lx DMT=%02lx, DCON=%08lx\n", @@ -132,7 +132,16 @@ dmadbg_showchan(const char *fname, int line, s3c2410_dma_chan_t *chan) chan->number, fname, line, chan->load_state, chan->curr, chan->next, chan->end); - dmadbg_showregs(fname, line, chan, &state); + dmadbg_dumpregs(fname, line, chan, &state); +} + +static void +dmadbg_showregs(const char *fname, int line, s3c2410_dma_chan_t *chan) +{ + struct s3c2410_dma_regstate state; + + dmadbg_capture(chan, &state); + dmadbg_dumpregs(fname, line, chan, &state); } #define dbg_showregs(chan) dmadbg_showregs(__FUNCTION__, __LINE__, (chan)) @@ -253,10 +262,14 @@ s3c2410_dma_loadbuffer(s3c2410_dma_chan_t *chan, buf->next); reload = (buf->next == NULL) ? S3C2410_DCON_NORELOAD : 0; } else { - pr_debug("load_state is %d => autoreload\n", chan->load_state); + //pr_debug("load_state is %d => autoreload\n", chan->load_state); reload = S3C2410_DCON_AUTORELOAD; } + if ((buf->data & 0xf0000000) != 0x30000000) { + dmawarn("dmaload: buffer is %p\n", (void *)buf->data); + } + writel(buf->data, chan->addr_reg); dma_wrreg(chan, S3C2410_DMA_DCON, @@ -370,7 +383,7 @@ static int s3c2410_dma_start(s3c2410_dma_chan_t *chan) tmp |= S3C2410_DMASKTRIG_ON; dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); - pr_debug("wrote %08lx to DMASKTRIG\n", tmp); + pr_debug("dma%d: %08lx to DMASKTRIG\n", chan->number, tmp); #if 0 /* the dma buffer loads should take care of clearing the AUTO @@ -384,7 +397,30 @@ static int s3c2410_dma_start(s3c2410_dma_chan_t *chan) dbg_showchan(chan); + /* if we've only loaded one buffer onto the channel, then chec + * to see if we have another, and if so, try and load it so when + * the first buffer is finished, the new one will be loaded onto + * the channel */ + + if (chan->next != NULL) { + if (chan->load_state == S3C2410_DMALOAD_1LOADED) { + + if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { + pr_debug("%s: buff not yet loaded, no more todo\n", + __FUNCTION__); + } else { + chan->load_state = S3C2410_DMALOAD_1RUNNING; + s3c2410_dma_loadbuffer(chan, chan->next); + } + + } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) { + s3c2410_dma_loadbuffer(chan, chan->next); + } + } + + local_irq_restore(flags); + return 0; } @@ -436,12 +472,11 @@ int s3c2410_dma_enqueue(unsigned int channel, void *id, buf = kmem_cache_alloc(dma_kmem, GFP_ATOMIC); if (buf == NULL) { pr_debug("%s: out of memory (%ld alloc)\n", - __FUNCTION__, sizeof(*buf)); + __FUNCTION__, (long)sizeof(*buf)); return -ENOMEM; } - pr_debug("%s: new buffer %p\n", __FUNCTION__, buf); - + //pr_debug("%s: new buffer %p\n", __FUNCTION__, buf); //dbg_showchan(chan); buf->next = NULL; @@ -537,14 +572,20 @@ s3c2410_dma_lastxfer(s3c2410_dma_chan_t *chan) case S3C2410_DMALOAD_1LOADED: if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { /* flag error? */ - printk(KERN_ERR "dma%d: timeout waiting for load\n", - chan->number); + printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n", + chan->number, __FUNCTION__); return; } break; + case S3C2410_DMALOAD_1LOADED_1RUNNING: + /* I belive in this case we do not have anything to do + * until the next buffer comes along, and we turn off the + * reload */ + return; + default: - pr_debug("dma%d: lastxfer: unhandled load_state %d with no next", + pr_debug("dma%d: lastxfer: unhandled load_state %d with no next\n", chan->number, chan->load_state); return; @@ -629,7 +670,14 @@ s3c2410_dma_irq(int irq, void *devpw, struct pt_regs *regs) } else { } - if (chan->next != NULL) { + /* only reload if the channel is still running... our buffer done + * routine may have altered the state by requesting the dma channel + * to stop or shutdown... */ + + /* todo: check that when the channel is shut-down from inside this + * function, we cope with unsetting reload, etc */ + + if (chan->next != NULL && chan->state != S3C2410_DMA_IDLE) { unsigned long flags; switch (chan->load_state) { @@ -644,8 +692,8 @@ s3c2410_dma_irq(int irq, void *devpw, struct pt_regs *regs) case S3C2410_DMALOAD_1LOADED: if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { /* flag error? */ - printk(KERN_ERR "dma%d: timeout waiting for load\n", - chan->number); + printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n", + chan->number, __FUNCTION__); return IRQ_HANDLED; } @@ -678,8 +726,6 @@ s3c2410_dma_irq(int irq, void *devpw, struct pt_regs *regs) return IRQ_HANDLED; } - - /* s3c2410_request_dma * * get control of an dma channel @@ -718,11 +764,17 @@ int s3c2410_dma_request(unsigned int channel, s3c2410_dma_client_t *client, pr_debug("dma%d: %s : requesting irq %d\n", channel, __FUNCTION__, chan->irq); + chan->irq_claimed = 1; + local_irq_restore(flags); + err = request_irq(chan->irq, s3c2410_dma_irq, IRQF_DISABLED, client->name, (void *)chan); + local_irq_save(flags); + if (err) { chan->in_use = 0; + chan->irq_claimed = 0; local_irq_restore(flags); printk(KERN_ERR "%s: cannot get IRQ %d for DMA %d\n", @@ -730,7 +782,6 @@ int s3c2410_dma_request(unsigned int channel, s3c2410_dma_client_t *client, return err; } - chan->irq_claimed = 1; chan->irq_enabled = 1; } @@ -810,6 +861,7 @@ static int s3c2410_dma_dostop(s3c2410_dma_chan_t *chan) tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); tmp |= S3C2410_DMASKTRIG_STOP; + //tmp &= ~S3C2410_DMASKTRIG_ON; dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp); #if 0 @@ -819,6 +871,7 @@ static int s3c2410_dma_dostop(s3c2410_dma_chan_t *chan) dma_wrreg(chan, S3C2410_DMA_DCON, tmp); #endif + /* should stop do this, or should we wait for flush? */ chan->state = S3C2410_DMA_IDLE; chan->load_state = S3C2410_DMALOAD_NONE; @@ -827,6 +880,22 @@ static int s3c2410_dma_dostop(s3c2410_dma_chan_t *chan) return 0; } +void s3c2410_dma_waitforstop(s3c2410_dma_chan_t *chan) +{ + unsigned long tmp; + unsigned int timeout = 0x10000; + + while (timeout-- > 0) { + tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG); + + if (!(tmp & S3C2410_DMASKTRIG_ON)) + return; + } + + pr_debug("dma%d: failed to stop?\n", chan->number); +} + + /* s3c2410_dma_flush * * stop the channel, and remove all current and pending transfers @@ -837,7 +906,9 @@ static int s3c2410_dma_flush(s3c2410_dma_chan_t *chan) s3c2410_dma_buf_t *buf, *next; unsigned long flags; - pr_debug("%s:\n", __FUNCTION__); + pr_debug("%s: chan %p (%d)\n", __FUNCTION__, chan, chan->number); + + dbg_showchan(chan); local_irq_save(flags); @@ -864,11 +935,64 @@ static int s3c2410_dma_flush(s3c2410_dma_chan_t *chan) } } + dbg_showregs(chan); + + s3c2410_dma_waitforstop(chan); + +#if 0 + /* should also clear interrupts, according to WinCE BSP */ + { + unsigned long tmp; + + tmp = dma_rdreg(chan, S3C2410_DMA_DCON); + tmp |= S3C2410_DCON_NORELOAD; + dma_wrreg(chan, S3C2410_DMA_DCON, tmp); + } +#endif + + dbg_showregs(chan); + local_irq_restore(flags); return 0; } +int +s3c2410_dma_started(s3c2410_dma_chan_t *chan) +{ + unsigned long flags; + + local_irq_save(flags); + + dbg_showchan(chan); + + /* if we've only loaded one buffer onto the channel, then chec + * to see if we have another, and if so, try and load it so when + * the first buffer is finished, the new one will be loaded onto + * the channel */ + + if (chan->next != NULL) { + if (chan->load_state == S3C2410_DMALOAD_1LOADED) { + + if (s3c2410_dma_waitforload(chan, __LINE__) == 0) { + pr_debug("%s: buff not yet loaded, no more todo\n", + __FUNCTION__); + } else { + chan->load_state = S3C2410_DMALOAD_1RUNNING; + s3c2410_dma_loadbuffer(chan, chan->next); + } + + } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) { + s3c2410_dma_loadbuffer(chan, chan->next); + } + } + + + local_irq_restore(flags); + + return 0; + +} int s3c2410_dma_ctrl(dmach_t channel, s3c2410_chan_op_t op) @@ -885,14 +1009,15 @@ s3c2410_dma_ctrl(dmach_t channel, s3c2410_chan_op_t op) return s3c2410_dma_dostop(chan); case S3C2410_DMAOP_PAUSE: - return -ENOENT; - case S3C2410_DMAOP_RESUME: return -ENOENT; case S3C2410_DMAOP_FLUSH: return s3c2410_dma_flush(chan); + case S3C2410_DMAOP_STARTED: + return s3c2410_dma_started(chan); + case S3C2410_DMAOP_TIMEOUT: return 0; diff --git a/include/asm-arm/arch-s3c2410/dma.h b/include/asm-arm/arch-s3c2410/dma.h index 72964f9..7463fd5 100644 --- a/include/asm-arm/arch-s3c2410/dma.h +++ b/include/asm-arm/arch-s3c2410/dma.h @@ -104,6 +104,7 @@ enum s3c2410_chan_op_e { S3C2410_DMAOP_RESUME, S3C2410_DMAOP_FLUSH, S3C2410_DMAOP_TIMEOUT, /* internal signal to handler */ + S3C2410_DMAOP_STARTED, /* indicate channel started */ }; typedef enum s3c2410_chan_op_e s3c2410_chan_op_t; -- 2.7.4