From f1acb878b6070941e844dfc4ca1b3b9e5a70426c Mon Sep 17 00:00:00 2001 From: Roel Kluin Date: Sat, 13 Feb 2010 15:54:03 +0100 Subject: iop-adma: redundant/wrong tests in iop_*_count()? When we reach the loop, len is at least 1, we only stay in the loop when len is at least MAX_BYTE_COUNT + 1, MAX_BYTE_COUNT is subtracted in each iteration. So when we leave the loop, or didn't take it, len is at least 1. Testing whether len is non-zero appears redundant. Signed-off-by: Roel Kluin Signed-off-by: Dan Williams --- arch/arm/include/asm/hardware/iop3xx-adma.h | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'arch') diff --git a/arch/arm/include/asm/hardware/iop3xx-adma.h b/arch/arm/include/asm/hardware/iop3xx-adma.h index 1a8c7279a28..9b28f1243bd 100644 --- a/arch/arm/include/asm/hardware/iop3xx-adma.h +++ b/arch/arm/include/asm/hardware/iop3xx-adma.h @@ -366,8 +366,7 @@ static inline int iop_chan_xor_slot_count(size_t len, int src_cnt, slot_cnt += *slots_per_op; } - if (len) - slot_cnt += *slots_per_op; + slot_cnt += *slots_per_op; return slot_cnt; } @@ -389,8 +388,7 @@ static inline int iop_chan_zero_sum_slot_count(size_t len, int src_cnt, slot_cnt += *slots_per_op; } - if (len) - slot_cnt += *slots_per_op; + slot_cnt += *slots_per_op; return slot_cnt; } @@ -737,10 +735,8 @@ iop_desc_set_zero_sum_byte_count(struct iop_adma_desc_slot *desc, u32 len) i += slots_per_op; } while (len > IOP_ADMA_ZERO_SUM_MAX_BYTE_COUNT); - if (len) { - iter = iop_hw_desc_slot_idx(hw_desc, i); - iter->byte_count = len; - } + iter = iop_hw_desc_slot_idx(hw_desc, i); + iter->byte_count = len; } } -- cgit v1.2.3-70-g09d2 From b87108a772e001af3fa79f9cfd87b190375f47a2 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Tue, 2 Mar 2010 14:17:20 -0700 Subject: DMAENGINE: COH 901 318 descriptor pool refactoring This centralize some spread-out initialization of descriptors into one function and cleans up the error paths. Signed-off-by: Linus Walleij Signed-off-by: Dan Williams --- arch/arm/mach-u300/include/mach/coh901318.h | 2 +- drivers/dma/coh901318.c | 54 +++++++++++++---------------- 2 files changed, 26 insertions(+), 30 deletions(-) (limited to 'arch') diff --git a/arch/arm/mach-u300/include/mach/coh901318.h b/arch/arm/mach-u300/include/mach/coh901318.h index f4cfee9c7d2..b8155b4e5ff 100644 --- a/arch/arm/mach-u300/include/mach/coh901318.h +++ b/arch/arm/mach-u300/include/mach/coh901318.h @@ -53,7 +53,7 @@ struct coh901318_params { * struct coh_dma_channel - dma channel base * @name: ascii name of dma channel * @number: channel id number - * @desc_nbr_max: number of preallocated descriptortors + * @desc_nbr_max: number of preallocated descriptors * @priority_high: prio of channel, 0 low otherwise high. * @param: configuration parameters * @dev_addr: physical address of periphal connected to channel diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c index f1bf4f74ad8..12a7a151be6 100644 --- a/drivers/dma/coh901318.c +++ b/drivers/dma/coh901318.c @@ -335,16 +335,22 @@ coh901318_desc_get(struct coh901318_chan *cohc) * TODO: alloc a pile of descs instead of just one, * avoid many small allocations. */ - desc = kmalloc(sizeof(struct coh901318_desc), GFP_NOWAIT); + desc = kzalloc(sizeof(struct coh901318_desc), GFP_NOWAIT); if (desc == NULL) goto out; INIT_LIST_HEAD(&desc->node); + dma_async_tx_descriptor_init(&desc->desc, &cohc->chan); } else { /* Reuse an old desc. */ desc = list_first_entry(&cohc->free, struct coh901318_desc, node); list_del(&desc->node); + /* Initialize it a bit so it's not insane */ + desc->sg = NULL; + desc->sg_len = 0; + desc->desc.callback = NULL; + desc->desc.callback_param = NULL; } out: @@ -885,6 +891,7 @@ coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, struct coh901318_chan *cohc = to_coh901318_chan(chan); int lli_len; u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last; + int ret; spin_lock_irqsave(&cohc->lock, flg); @@ -905,22 +912,19 @@ coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, if (data == NULL) goto err; - cohd = coh901318_desc_get(cohc); - cohd->sg = NULL; - cohd->sg_len = 0; - cohd->data = data; - - cohd->pending_irqs = - coh901318_lli_fill_memcpy( - &cohc->base->pool, data, src, size, dest, - cohc_chan_param(cohc)->ctrl_lli_chained, - ctrl_last); - cohd->flags = flags; + ret = coh901318_lli_fill_memcpy( + &cohc->base->pool, data, src, size, dest, + cohc_chan_param(cohc)->ctrl_lli_chained, + ctrl_last); + if (ret) + goto err; COH_DBG(coh901318_list_print(cohc, data)); - dma_async_tx_descriptor_init(&cohd->desc, chan); - + /* Pick a descriptor to handle this transfer */ + cohd = coh901318_desc_get(cohc); + cohd->data = data; + cohd->flags = flags; cohd->desc.tx_submit = coh901318_tx_submit; spin_unlock_irqrestore(&cohc->lock, flg); @@ -962,11 +966,6 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, /* Trigger interrupt after last lli */ ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE; - cohd = coh901318_desc_get(cohc); - cohd->sg = NULL; - cohd->sg_len = 0; - cohd->dir = direction; - if (direction == DMA_TO_DEVICE) { u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE | COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE; @@ -984,11 +983,6 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, } else goto err_direction; - dma_async_tx_descriptor_init(&cohd->desc, chan); - - cohd->desc.tx_submit = coh901318_tx_submit; - - /* The dma only supports transmitting packages up to * MAX_DMA_PACKET_SIZE. Calculate to total number of * dma elemts required to send the entire sg list @@ -1023,19 +1017,21 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, ctrl, ctrl_last, direction, COH901318_CX_CTRL_TC_IRQ_ENABLE); - cohd->data = data; - - cohd->flags = flags; COH_DBG(coh901318_list_print(cohc, data)); + /* Pick a descriptor to handle this transfer */ + cohd = coh901318_desc_get(cohc); + cohd->dir = direction; + cohd->flags = flags; + cohd->desc.tx_submit = coh901318_tx_submit; + cohd->data = data; + spin_unlock_irqrestore(&cohc->lock, flg); return &cohd->desc; err_dma_alloc: err_direction: - coh901318_desc_remove(cohd); - coh901318_desc_free(cohc, cohd); spin_unlock_irqrestore(&cohc->lock, flg); out: return NULL; -- cgit v1.2.3-70-g09d2