On Mon, Dec 15, 2014 at 10:32:28AM +0800, xuelin.shi@xxxxxxxxxxxxx wrote: > +/* Copy descriptor from per chan software queue into hardware job ring */ > +static void fsl_re_issue_pending(struct dma_chan *chan) > +{ > + struct fsl_re_chan *re_chan; > + int avail; > + struct fsl_re_desc *desc, *_desc; > + unsigned long flags; > + > + re_chan = container_of(chan, struct fsl_re_chan, chan); > + > + spin_lock_irqsave(&re_chan->desc_lock, flags); > + avail = FSL_RE_SLOT_AVAIL( > + in_be32(&re_chan->jrregs->inbring_slot_avail)); okay this seems slots avail in hw > + > + list_for_each_entry_safe(desc, _desc, &re_chan->submit_q, node) { > + if (!avail) > + break; and why break inside the loop. You shouldn't even enter this only to keep breaking! > +static void fsl_re_dequeue(unsigned long data) > +{ > + struct fsl_re_chan *re_chan; > + struct fsl_re_desc *desc, *_desc; > + struct fsl_re_hw_desc *hwdesc; > + unsigned long flags; > + unsigned int count, oub_count; > + int found; > + > + re_chan = dev_get_drvdata((struct device *)data); > + > + fsl_re_cleanup_descs(re_chan); > + > + spin_lock_irqsave(&re_chan->desc_lock, flags); > + count = FSL_RE_SLOT_FULL(in_be32(&re_chan->jrregs->oubring_slot_full)); > + while (count--) { > + found = 0; > + hwdesc = &re_chan->oub_ring_virt_addr[re_chan->oub_count]; > + list_for_each_entry_safe(desc, _desc, &re_chan->active_q, > + node) { > + /* compare the hw dma addr to find the completed */ > + if (desc->hwdesc.lbea32 == hwdesc->lbea32 && > + desc->hwdesc.addr_low == hwdesc->addr_low) { > + found = 1; > + break; > + } > + } > + > + BUG_ON(!found); you are killing the machine here. I don't think it too severe and can't be handled gracefully? > +static struct fsl_re_desc *fsl_re_chan_alloc_desc(struct fsl_re_chan *re_chan, > + unsigned long flags) > +{ > + struct fsl_re_desc *desc = NULL; > + void *cf; > + dma_addr_t paddr; > + unsigned long lock_flag; > + > + fsl_re_cleanup_descs(re_chan); > + > + spin_lock_irqsave(&re_chan->desc_lock, lock_flag); > + if (!list_empty(&re_chan->free_q)) { > + /* take one desc from free_q */ > + desc = list_first_entry(&re_chan->free_q, > + struct fsl_re_desc, node); > + list_del(&desc->node); > + > + desc->async_tx.flags = flags; > + } > + spin_unlock_irqrestore(&re_chan->desc_lock, lock_flag); > + > + if (!desc) { > + desc = kzalloc(sizeof(*desc), GFP_NOWAIT); > + cf = dma_pool_alloc(re_chan->re_dev->cf_desc_pool, GFP_NOWAIT, > + &paddr); > + if (!desc || !cf) { > + kfree(desc); and this is buggy, you can fail in desc while cf is okay..! > + return NULL; > + } > + > + desc = fsl_re_init_desc(re_chan, desc, cf, paddr); > + desc->async_tx.flags = flags; > + > + spin_lock_irqsave(&re_chan->desc_lock, lock_flag); > + re_chan->alloc_count++; > + spin_unlock_irqrestore(&re_chan->desc_lock, lock_flag); > + } > + > + return desc; > +} > + > +static struct dma_async_tx_descriptor *fsl_re_prep_dma_genq( > + struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src, > + unsigned int src_cnt, const unsigned char *scf, size_t len, > + unsigned long flags) > +{ > + struct fsl_re_chan *re_chan; > + struct fsl_re_desc *desc; > + struct fsl_re_xor_cdb *xor; > + struct fsl_re_cmpnd_frame *cf; > + u32 cdb; > + unsigned int i, j; > + unsigned int save_src_cnt = src_cnt; > + int cont_q = 0; > + > + if (len > FSL_RE_MAX_DATA_LEN) { > + pr_err("Length greater than %d not supported\n", > + FSL_RE_MAX_DATA_LEN); printing length will be helpful btw whats wrong with dev_err. You do realize that someone who seems this will have no clue which device is reporting this > + > +static int fsl_re_alloc_chan_resources(struct dma_chan *chan) > +{ > + struct fsl_re_chan *re_chan; > + struct fsl_re_desc *desc; > + void *cf; > + dma_addr_t paddr; > + int i; > + > + re_chan = container_of(chan, struct fsl_re_chan, chan); > + for (i = 0; i < FSL_RE_MIN_DESCS; i++) { > + desc = kzalloc(sizeof(*desc), GFP_KERNEL); > + cf = dma_pool_alloc(re_chan->re_dev->cf_desc_pool, GFP_KERNEL, > + &paddr); > + if (!desc || !cf) { > + kfree(desc); > + break; here as well... > + /* Output Ring */ > + __be32 oubring_base_h; /* Outbound Ring Base Address Register - High */ > + __be32 oubring_base_l; /* Outbound Ring Base Address Register - Low */ > + __be32 oubring_size; /* Outbound Ring Size Register */ > + u8 rsvd8[4]; > + __be32 oubring_job_rmvd; /* Outbound Ring Job Removed Register */ > + u8 rsvd9[4]; > + __be32 oubring_slot_full; /* Outbound Ring Slot Full Register */ > + u8 rsvd10[4]; > + __be32 oubring_prdcr_indx; /* Outbound Ring Producer Index */ > +}; is the dma BE always irresepective of CPU type or thats dependent on cpu type too? -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html