diff options
| -rw-r--r-- | sound/ppc/pmac.c | 107 |
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; } |