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-rw-r--r--sound/ppc/pmac.c107
1 files changed, 102 insertions, 5 deletions
diff --git a/sound/ppc/pmac.c b/sound/ppc/pmac.c
index aada1d7..613a565 100644
--- a/sound/ppc/pmac.c
+++ b/sound/ppc/pmac.c
@@ -44,6 +44,18 @@ static int tumbler_freqs[1] = {
44100
};
+
+/*
+ * we will allocate a single 'emergency' dbdma cmd block to use if the
+ * tx status comes up "DEAD". This happens on some PowerComputing Pmac
+ * clones, either owing to a bug in dbdma or some interaction between
+ * IDE and sound. However, this measure would deal with DEAD status if
+ * it appeared elsewhere.
+ */
+static struct pmac_dbdma emergency_dbdma;
+static int emergency_in_use;
+
+
/*
* allocate DBDMA command arrays
*/
@@ -375,6 +387,75 @@ static snd_pcm_uframes_t snd_pmac_capture_pointer(struct snd_pcm_substream *subs
/*
+ * Handle DEAD DMA transfers:
+ * if the TX status comes up "DEAD" - reported on some Power Computing machines
+ * we need to re-start the dbdma - but from a different physical start address
+ * and with a different transfer length. It would get very messy to do this
+ * with the normal dbdma_cmd blocks - we would have to re-write the buffer start
+ * addresses each time. So, we will keep a single dbdma_cmd block which can be
+ * fiddled with.
+ * When DEAD status is first reported the content of the faulted dbdma block is
+ * copied into the emergency buffer and we note that the buffer is in use.
+ * we then bump the start physical address by the amount that was successfully
+ * output before it died.
+ * On any subsequent DEAD result we just do the bump-ups (we know that we are
+ * already using the emergency dbdma_cmd).
+ * CHECK: this just tries to "do it". It is possible that we should abandon
+ * xfers when the number of residual bytes gets below a certain value - I can
+ * see that this might cause a loop-forever if a too small transfer causes
+ * DEAD status. However this is a TODO for now - we'll see what gets reported.
+ * When we get a successful transfer result with the emergency buffer we just
+ * pretend that it completed using the original dmdma_cmd and carry on. The
+ * 'next_cmd' field will already point back to the original loop of blocks.
+ */
+static inline void snd_pmac_pcm_dead_xfer(struct pmac_stream *rec,
+ volatile struct dbdma_cmd __iomem *cp)
+{
+ unsigned short req, res ;
+ unsigned int phy ;
+
+ /* printk(KERN_WARNING "snd-powermac: DMA died - patching it up!\n"); */
+
+ /* to clear DEAD status we must first clear RUN
+ set it to quiescent to be on the safe side */
+ (void)in_le32(&rec->dma->status);
+ out_le32(&rec->dma->control, (RUN|PAUSE|FLUSH|WAKE) << 16);
+
+ if (!emergency_in_use) { /* new problem */
+ memcpy((void *)emergency_dbdma.cmds, (void *)cp,
+ sizeof(struct dbdma_cmd));
+ emergency_in_use = 1;
+ st_le16(&cp->xfer_status, 0);
+ st_le16(&cp->req_count, rec->period_size);
+ cp = emergency_dbdma.cmds;
+ }
+
+ /* now bump the values to reflect the amount
+ we haven't yet shifted */
+ req = ld_le16(&cp->req_count);
+ res = ld_le16(&cp->res_count);
+ phy = ld_le32(&cp->phy_addr);
+ phy += (req - res);
+ st_le16(&cp->req_count, res);
+ st_le16(&cp->res_count, 0);
+ st_le16(&cp->xfer_status, 0);
+ st_le32(&cp->phy_addr, phy);
+
+ st_le32(&cp->cmd_dep, rec->cmd.addr
+ + sizeof(struct dbdma_cmd)*((rec->cur_period+1)%rec->nperiods));
+
+ st_le16(&cp->command, OUTPUT_MORE | BR_ALWAYS | INTR_ALWAYS);
+
+ /* point at our patched up command block */
+ out_le32(&rec->dma->cmdptr, emergency_dbdma.addr);
+
+ /* we must re-start the controller */
+ (void)in_le32(&rec->dma->status);
+ /* should complete clearing the DEAD status */
+ out_le32(&rec->dma->control, ((RUN|WAKE) << 16) + (RUN|WAKE));
+}
+
+/*
* update playback/capture pointer from interrupts
*/
static void snd_pmac_pcm_update(struct snd_pmac *chip, struct pmac_stream *rec)
@@ -385,11 +466,26 @@ static void snd_pmac_pcm_update(struct snd_pmac *chip, struct pmac_stream *rec)
spin_lock(&chip->reg_lock);
if (rec->running) {
- cp = &rec->cmd.cmds[rec->cur_period];
for (c = 0; c < rec->nperiods; c++) { /* at most all fragments */
+
+ if (emergency_in_use) /* already using DEAD xfer? */
+ cp = emergency_dbdma.cmds;
+ else
+ cp = &rec->cmd.cmds[rec->cur_period];
+
stat = ld_le16(&cp->xfer_status);
+
+ if (stat & DEAD) {
+ snd_pmac_pcm_dead_xfer(rec, cp);
+ break; /* this block is still going */
+ }
+
+ if (emergency_in_use)
+ emergency_in_use = 0 ; /* done that */
+
if (! (stat & ACTIVE))
break;
+
/*printk("update frag %d\n", rec->cur_period);*/
st_le16(&cp->xfer_status, 0);
st_le16(&cp->req_count, rec->period_size);
@@ -397,9 +493,8 @@ static void snd_pmac_pcm_update(struct snd_pmac *chip, struct pmac_stream *rec)
rec->cur_period++;
if (rec->cur_period >= rec->nperiods) {
rec->cur_period = 0;
- cp = rec->cmd.cmds;
- } else
- cp++;
+ }
+
spin_unlock(&chip->reg_lock);
snd_pcm_period_elapsed(rec->substream);
spin_lock(&chip->reg_lock);
@@ -769,6 +864,7 @@ static int snd_pmac_free(struct snd_pmac *chip)
snd_pmac_dbdma_free(chip, &chip->playback.cmd);
snd_pmac_dbdma_free(chip, &chip->capture.cmd);
snd_pmac_dbdma_free(chip, &chip->extra_dma);
+ snd_pmac_dbdma_free(chip, &emergency_dbdma);
if (chip->macio_base)
iounmap(chip->macio_base);
if (chip->latch_base)
@@ -1107,7 +1203,8 @@ int __init snd_pmac_new(struct snd_card *card, struct snd_pmac **chip_return)
if (snd_pmac_dbdma_alloc(chip, &chip->playback.cmd, PMAC_MAX_FRAGS + 1) < 0 ||
snd_pmac_dbdma_alloc(chip, &chip->capture.cmd, PMAC_MAX_FRAGS + 1) < 0 ||
- snd_pmac_dbdma_alloc(chip, &chip->extra_dma, 2) < 0) {
+ snd_pmac_dbdma_alloc(chip, &chip->extra_dma, 2) < 0 ||
+ snd_pmac_dbdma_alloc(chip, &emergency_dbdma, 2) < 0) {
err = -ENOMEM;
goto __error;
}