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authorBen Dooks <ben-linux@fluff.org>2006-08-18 15:32:10 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-08-18 15:32:10 +0100
commitf57e1abd1bb297994c7398478b4c37e628095243 (patch)
treef25447fd37bf0b56c5aa8b197570ac802d8ac904 /arch
parenta0c5a64552e3c57d7f9eb593c6ce21a285ac86b4 (diff)
[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 <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mach-s3c2410/dma.c163
1 files changed, 144 insertions, 19 deletions
diff --git a/arch/arm/mach-s3c2410/dma.c b/arch/arm/mach-s3c2410/dma.c
index 094cc52745c..25855452fe8 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;