From fd009035047941fe21622b09665423f1043f0507 Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Mon, 23 Sep 2013 18:05:13 -0500 Subject: dma: edma: Split out PaRAM set calculations into its own function PaRAM set calculation is abstracted into its own function to enable better reuse for other DMA cases such as cyclic. We adapt the Slave SG case to use the new function. This provides a much cleaner abstraction to the internals of the PaRAM set. However, any PaRAM attributes that are not common to all DMA types must be set separately such as setting of interrupts. This function takes care of the most-common attributes. Also added comments clarifying A-sync case calculations. Signed-off-by: Joel Fernandes Signed-off-by: Vinod Koul --- drivers/dma/edma.c | 198 ++++++++++++++++++++++++++++++++++------------------- 1 file changed, 126 insertions(+), 72 deletions(-) (limited to 'drivers/dma/edma.c') diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 098a8da450f0..e47e3c9e37b2 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -250,6 +250,117 @@ static int edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, return ret; } +/* + * A PaRAM set configuration abstraction used by other modes + * @chan: Channel who's PaRAM set we're configuring + * @pset: PaRAM set to initialize and setup. + * @src_addr: Source address of the DMA + * @dst_addr: Destination address of the DMA + * @burst: In units of dev_width, how much to send + * @dev_width: How much is the dev_width + * @dma_length: Total length of the DMA transfer + * @direction: Direction of the transfer + */ +static int edma_config_pset(struct dma_chan *chan, struct edmacc_param *pset, + dma_addr_t src_addr, dma_addr_t dst_addr, u32 burst, + enum dma_slave_buswidth dev_width, unsigned int dma_length, + enum dma_transfer_direction direction) +{ + struct edma_chan *echan = to_edma_chan(chan); + struct device *dev = chan->device->dev; + int acnt, bcnt, ccnt, cidx; + int src_bidx, dst_bidx, src_cidx, dst_cidx; + int absync; + + acnt = dev_width; + /* + * If the maxburst is equal to the fifo width, use + * A-synced transfers. This allows for large contiguous + * buffer transfers using only one PaRAM set. + */ + if (burst == 1) { + /* + * For the A-sync case, bcnt and ccnt are the remainder + * and quotient respectively of the division of: + * (dma_length / acnt) by (SZ_64K -1). This is so + * that in case bcnt over flows, we have ccnt to use. + * Note: In A-sync tranfer only, bcntrld is used, but it + * only applies for sg_dma_len(sg) >= SZ_64K. + * In this case, the best way adopted is- bccnt for the + * first frame will be the remainder below. Then for + * every successive frame, bcnt will be SZ_64K-1. This + * is assured as bcntrld = 0xffff in end of function. + */ + absync = false; + ccnt = dma_length / acnt / (SZ_64K - 1); + bcnt = dma_length / acnt - ccnt * (SZ_64K - 1); + /* + * If bcnt is non-zero, we have a remainder and hence an + * extra frame to transfer, so increment ccnt. + */ + if (bcnt) + ccnt++; + else + bcnt = SZ_64K - 1; + cidx = acnt; + } else { + /* + * If maxburst is greater than the fifo address_width, + * use AB-synced transfers where A count is the fifo + * address_width and B count is the maxburst. In this + * case, we are limited to transfers of C count frames + * of (address_width * maxburst) where C count is limited + * to SZ_64K-1. This places an upper bound on the length + * of an SG segment that can be handled. + */ + absync = true; + bcnt = burst; + ccnt = dma_length / (acnt * bcnt); + if (ccnt > (SZ_64K - 1)) { + dev_err(dev, "Exceeded max SG segment size\n"); + return -EINVAL; + } + cidx = acnt * bcnt; + } + + if (direction == DMA_MEM_TO_DEV) { + src_bidx = acnt; + src_cidx = cidx; + dst_bidx = 0; + dst_cidx = 0; + } else if (direction == DMA_DEV_TO_MEM) { + src_bidx = 0; + src_cidx = 0; + dst_bidx = acnt; + dst_cidx = cidx; + } else { + dev_err(dev, "%s: direction not implemented yet\n", __func__); + return -EINVAL; + } + + pset->opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num)); + /* Configure A or AB synchronized transfers */ + if (absync) + pset->opt |= SYNCDIM; + + pset->src = src_addr; + pset->dst = dst_addr; + + pset->src_dst_bidx = (dst_bidx << 16) | src_bidx; + pset->src_dst_cidx = (dst_cidx << 16) | src_cidx; + + pset->a_b_cnt = bcnt << 16 | acnt; + pset->ccnt = ccnt; + /* + * Only time when (bcntrld) auto reload is required is for + * A-sync case, and in this case, a requirement of reload value + * of SZ_64K-1 only is assured. 'link' is initially set to NULL + * and then later will be populated by edma_execute. + */ + pset->link_bcntrld = 0xffffffff; + return absync; +} + static struct dma_async_tx_descriptor *edma_prep_slave_sg( struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction direction, @@ -258,23 +369,21 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( struct edma_chan *echan = to_edma_chan(chan); struct device *dev = chan->device->dev; struct edma_desc *edesc; - dma_addr_t dev_addr; + dma_addr_t src_addr = 0, dst_addr = 0; enum dma_slave_buswidth dev_width; u32 burst; struct scatterlist *sg; - int acnt, bcnt, ccnt, src, dst, cidx; - int src_bidx, dst_bidx, src_cidx, dst_cidx; - int i, nslots; + int i, nslots, ret; if (unlikely(!echan || !sgl || !sg_len)) return NULL; if (direction == DMA_DEV_TO_MEM) { - dev_addr = echan->cfg.src_addr; + src_addr = echan->cfg.src_addr; dev_width = echan->cfg.src_addr_width; burst = echan->cfg.src_maxburst; } else if (direction == DMA_MEM_TO_DEV) { - dev_addr = echan->cfg.dst_addr; + dst_addr = echan->cfg.dst_addr; dev_width = echan->cfg.dst_addr_width; burst = echan->cfg.dst_maxburst; } else { @@ -313,63 +422,19 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( /* Configure PaRAM sets for each SG */ for_each_sg(sgl, sg, sg_len, i) { + /* Get address for each SG */ + if (direction == DMA_DEV_TO_MEM) + dst_addr = sg_dma_address(sg); + else + src_addr = sg_dma_address(sg); - acnt = dev_width; - - /* - * If the maxburst is equal to the fifo width, use - * A-synced transfers. This allows for large contiguous - * buffer transfers using only one PaRAM set. - */ - if (burst == 1) { - edesc->absync = false; - ccnt = sg_dma_len(sg) / acnt / (SZ_64K - 1); - bcnt = sg_dma_len(sg) / acnt - ccnt * (SZ_64K - 1); - if (bcnt) - ccnt++; - else - bcnt = SZ_64K - 1; - cidx = acnt; - /* - * If maxburst is greater than the fifo address_width, - * use AB-synced transfers where A count is the fifo - * address_width and B count is the maxburst. In this - * case, we are limited to transfers of C count frames - * of (address_width * maxburst) where C count is limited - * to SZ_64K-1. This places an upper bound on the length - * of an SG segment that can be handled. - */ - } else { - edesc->absync = true; - bcnt = burst; - ccnt = sg_dma_len(sg) / (acnt * bcnt); - if (ccnt > (SZ_64K - 1)) { - dev_err(dev, "Exceeded max SG segment size\n"); - return NULL; - } - cidx = acnt * bcnt; - } - - if (direction == DMA_MEM_TO_DEV) { - src = sg_dma_address(sg); - dst = dev_addr; - src_bidx = acnt; - src_cidx = cidx; - dst_bidx = 0; - dst_cidx = 0; - } else { - src = dev_addr; - dst = sg_dma_address(sg); - src_bidx = 0; - src_cidx = 0; - dst_bidx = acnt; - dst_cidx = cidx; - } + ret = edma_config_pset(chan, &edesc->pset[i], src_addr, + dst_addr, burst, dev_width, + sg_dma_len(sg), direction); + if (ret < 0) + return NULL; - edesc->pset[i].opt = EDMA_TCC(EDMA_CHAN_SLOT(echan->ch_num)); - /* Configure A or AB synchronized transfers */ - if (edesc->absync) - edesc->pset[i].opt |= SYNCDIM; + edesc->absync = ret; /* If this is the last in a current SG set of transactions, enable interrupts so that next set is processed */ @@ -379,17 +444,6 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( /* If this is the last set, enable completion interrupt flag */ if (i == sg_len - 1) edesc->pset[i].opt |= TCINTEN; - - edesc->pset[i].src = src; - edesc->pset[i].dst = dst; - - edesc->pset[i].src_dst_bidx = (dst_bidx << 16) | src_bidx; - edesc->pset[i].src_dst_cidx = (dst_cidx << 16) | src_cidx; - - edesc->pset[i].a_b_cnt = bcnt << 16 | acnt; - edesc->pset[i].ccnt = ccnt; - edesc->pset[i].link_bcntrld = 0xffffffff; - } return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags); -- cgit v1.2.3 From 2abd5f1b97fce6e197be01d67a9567c7793c80d3 Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Mon, 23 Sep 2013 18:05:15 -0500 Subject: dma: edma: Increase maximum SG limit to 20 davinci-pcm uses 16 as the no.of periods. With this, in EDMA we have to allocate atleast 17 slots: 1 slot for channel, and 16 slots the periods. Due to this, the MAX_NR_SG limitation causes problems, set it to 20 to make cyclic DMA work when davinci-pcm is converted to use DMA Engine. Also add a comment clarifying this. Signed-off-by: Joel Fernandes Signed-off-by: Vinod Koul --- drivers/dma/edma.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/dma/edma.c') diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index e47e3c9e37b2..79b046b3e2f0 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -46,8 +46,14 @@ #define EDMA_CHANS 64 #endif /* CONFIG_ARCH_DAVINCI_DA8XX */ -/* Max of 16 segments per channel to conserve PaRAM slots */ -#define MAX_NR_SG 16 +/* + * Max of 20 segments per channel to conserve PaRAM slots + * Also note that MAX_NR_SG should be atleast the no.of periods + * that are required for ASoC, otherwise DMA prep calls will + * fail. Today davinci-pcm is the only user of this driver and + * requires atleast 17 slots, so we setup the default to 20. + */ +#define MAX_NR_SG 20 #define EDMA_MAX_SLOTS MAX_NR_SG #define EDMA_DESCRIPTORS 16 -- cgit v1.2.3 From 9d386ec590a9455733d6fad3e4d1a4b2babc490c Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Wed, 16 Oct 2013 13:42:15 +0530 Subject: dmaengine: edma: use DMA_COMPLETE for dma completion status Tested-by: Joel Fernandes Acked-by: Dan Williams Acked-by: Linus Walleij Signed-off-by: Vinod Koul --- drivers/dma/edma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/dma/edma.c') diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 098a8da450f0..29fa35807f09 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -576,7 +576,7 @@ static enum dma_status edma_tx_status(struct dma_chan *chan, unsigned long flags; ret = dma_cookie_status(chan, cookie, txstate); - if (ret == DMA_SUCCESS || !txstate) + if (ret == DMA_COMPLETE || !txstate) return ret; spin_lock_irqsave(&echan->vchan.lock, flags); -- cgit v1.2.3 From db60d8da8f643586c95f8fc3e383954f8c57f1f3 Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Wed, 30 Oct 2013 18:22:30 +0530 Subject: dmanengine: fix edma driver to not define DMA_COMPLETE edma header defines DMA_COMPLETE, this causes issues as commit adfedd9a32e4 move DMA_SUCCESS to DMA_COMPLETE. edma should properly namespace its defines and needs a future fix Reported-by: Olof Johansson Signed-off-by: Vinod Koul --- arch/arm/common/edma.c | 4 ++-- drivers/dma/edma.c | 4 ++-- include/linux/platform_data/edma.h | 8 ++++---- 3 files changed, 8 insertions(+), 8 deletions(-) (limited to 'drivers/dma/edma.c') diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c index 8e1a0245907f..41bca32409fc 100644 --- a/arch/arm/common/edma.c +++ b/arch/arm/common/edma.c @@ -404,7 +404,7 @@ static irqreturn_t dma_irq_handler(int irq, void *data) BIT(slot)); if (edma_cc[ctlr]->intr_data[channel].callback) edma_cc[ctlr]->intr_data[channel].callback( - channel, DMA_COMPLETE, + channel, EDMA_DMA_COMPLETE, edma_cc[ctlr]->intr_data[channel].data); } } while (sh_ipr); @@ -459,7 +459,7 @@ static irqreturn_t dma_ccerr_handler(int irq, void *data) callback) { edma_cc[ctlr]->intr_data[k]. callback(k, - DMA_CC_ERROR, + EDMA_DMA_CC_ERROR, edma_cc[ctlr]->intr_data [k].data); } diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 29fa35807f09..cb69f3a674e0 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -407,7 +407,7 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data) edma_pause(echan->ch_num); switch (ch_status) { - case DMA_COMPLETE: + case EDMA_DMA_COMPLETE: spin_lock_irqsave(&echan->vchan.lock, flags); edesc = echan->edesc; @@ -426,7 +426,7 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data) spin_unlock_irqrestore(&echan->vchan.lock, flags); break; - case DMA_CC_ERROR: + case EDMA_DMA_CC_ERROR: spin_lock_irqsave(&echan->vchan.lock, flags); edma_read_slot(EDMA_CHAN_SLOT(echan->slot[0]), &p); diff --git a/include/linux/platform_data/edma.h b/include/linux/platform_data/edma.h index 179fb91bb5f2..f50821cb64be 100644 --- a/include/linux/platform_data/edma.h +++ b/include/linux/platform_data/edma.h @@ -67,10 +67,10 @@ struct edmacc_param { #define ITCCHEN BIT(23) /*ch_status paramater of callback function possible values*/ -#define DMA_COMPLETE 1 -#define DMA_CC_ERROR 2 -#define DMA_TC1_ERROR 3 -#define DMA_TC2_ERROR 4 +#define EDMA_DMA_COMPLETE 1 +#define EDMA_DMA_CC_ERROR 2 +#define EDMA_DMA_TC1_ERROR 3 +#define EDMA_DMA_TC2_ERROR 4 enum address_mode { INCR = 0, -- cgit v1.2.3 From 50a9c70714dfb17a85a3fb762675a64f598d504b Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Thu, 31 Oct 2013 16:31:23 -0500 Subject: dma: edma: Add support for Cyclic DMA Using the PaRAM configuration function that we split for reuse by the different DMA types, we implement Cyclic DMA support. For the cyclic case, we pass different configuration parameters to this function, and handle all the Cyclic-specific functionality separately. Callbacks to the DMA users are handled using vchan_cyclic_callback in the virt-dma layer. Linking is handled the same way as the slave SG case except for the last slot where we link it back to the first one in a cyclic fashion. For continuity, we check for cases where no.of periods is great than the MAX number of slots the driver can allocate for a particular descriptor and error out on such cases. Signed-off-by: Joel Fernandes Signed-off-by: Vinod Koul --- drivers/dma/edma.c | 159 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 151 insertions(+), 8 deletions(-) (limited to 'drivers/dma/edma.c') diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 183ec85cb6ca..592f3be8b435 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -60,6 +60,7 @@ struct edma_desc { struct virt_dma_desc vdesc; struct list_head node; + int cyclic; int absync; int pset_nr; int processed; @@ -173,8 +174,13 @@ static void edma_execute(struct edma_chan *echan) * then setup a link to the dummy slot, this results in all future * events being absorbed and that's OK because we're done */ - if (edesc->processed == edesc->pset_nr) - edma_link(echan->slot[nslots-1], echan->ecc->dummy_slot); + if (edesc->processed == edesc->pset_nr) { + if (edesc->cyclic) + edma_link(echan->slot[nslots-1], echan->slot[1]); + else + edma_link(echan->slot[nslots-1], + echan->ecc->dummy_slot); + } edma_resume(echan->ch_num); @@ -459,6 +465,138 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags); } +static struct dma_async_tx_descriptor *edma_prep_dma_cyclic( + struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction direction, + unsigned long tx_flags, void *context) +{ + struct edma_chan *echan = to_edma_chan(chan); + struct device *dev = chan->device->dev; + struct edma_desc *edesc; + dma_addr_t src_addr, dst_addr; + enum dma_slave_buswidth dev_width; + u32 burst; + int i, ret, nslots; + + if (unlikely(!echan || !buf_len || !period_len)) + return NULL; + + if (direction == DMA_DEV_TO_MEM) { + src_addr = echan->cfg.src_addr; + dst_addr = buf_addr; + dev_width = echan->cfg.src_addr_width; + burst = echan->cfg.src_maxburst; + } else if (direction == DMA_MEM_TO_DEV) { + src_addr = buf_addr; + dst_addr = echan->cfg.dst_addr; + dev_width = echan->cfg.dst_addr_width; + burst = echan->cfg.dst_maxburst; + } else { + dev_err(dev, "%s: bad direction?\n", __func__); + return NULL; + } + + if (dev_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) { + dev_err(dev, "Undefined slave buswidth\n"); + return NULL; + } + + if (unlikely(buf_len % period_len)) { + dev_err(dev, "Period should be multiple of Buffer length\n"); + return NULL; + } + + nslots = (buf_len / period_len) + 1; + + /* + * Cyclic DMA users such as audio cannot tolerate delays introduced + * by cases where the number of periods is more than the maximum + * number of SGs the EDMA driver can handle at a time. For DMA types + * such as Slave SGs, such delays are tolerable and synchronized, + * but the synchronization is difficult to achieve with Cyclic and + * cannot be guaranteed, so we error out early. + */ + if (nslots > MAX_NR_SG) + return NULL; + + edesc = kzalloc(sizeof(*edesc) + nslots * + sizeof(edesc->pset[0]), GFP_ATOMIC); + if (!edesc) { + dev_dbg(dev, "Failed to allocate a descriptor\n"); + return NULL; + } + + edesc->cyclic = 1; + edesc->pset_nr = nslots; + + dev_dbg(dev, "%s: nslots=%d\n", __func__, nslots); + dev_dbg(dev, "%s: period_len=%d\n", __func__, period_len); + dev_dbg(dev, "%s: buf_len=%d\n", __func__, buf_len); + + for (i = 0; i < nslots; i++) { + /* Allocate a PaRAM slot, if needed */ + if (echan->slot[i] < 0) { + echan->slot[i] = + edma_alloc_slot(EDMA_CTLR(echan->ch_num), + EDMA_SLOT_ANY); + if (echan->slot[i] < 0) { + dev_err(dev, "Failed to allocate slot\n"); + return NULL; + } + } + + if (i == nslots - 1) { + memcpy(&edesc->pset[i], &edesc->pset[0], + sizeof(edesc->pset[0])); + break; + } + + ret = edma_config_pset(chan, &edesc->pset[i], src_addr, + dst_addr, burst, dev_width, period_len, + direction); + if (ret < 0) + return NULL; + + if (direction == DMA_DEV_TO_MEM) + dst_addr += period_len; + else + src_addr += period_len; + + dev_dbg(dev, "%s: Configure period %d of buf:\n", __func__, i); + dev_dbg(dev, + "\n pset[%d]:\n" + " chnum\t%d\n" + " slot\t%d\n" + " opt\t%08x\n" + " src\t%08x\n" + " dst\t%08x\n" + " abcnt\t%08x\n" + " ccnt\t%08x\n" + " bidx\t%08x\n" + " cidx\t%08x\n" + " lkrld\t%08x\n", + i, echan->ch_num, echan->slot[i], + edesc->pset[i].opt, + edesc->pset[i].src, + edesc->pset[i].dst, + edesc->pset[i].a_b_cnt, + edesc->pset[i].ccnt, + edesc->pset[i].src_dst_bidx, + edesc->pset[i].src_dst_cidx, + edesc->pset[i].link_bcntrld); + + edesc->absync = ret; + + /* + * Enable interrupts for every period because callback + * has to be called for every period. + */ + edesc->pset[i].opt |= TCINTEN; + } + + return vchan_tx_prep(&echan->vchan, &edesc->vdesc, tx_flags); +} + static void edma_callback(unsigned ch_num, u16 ch_status, void *data) { struct edma_chan *echan = data; @@ -467,24 +605,28 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data) unsigned long flags; struct edmacc_param p; - /* Pause the channel */ - edma_pause(echan->ch_num); + edesc = echan->edesc; + + /* Pause the channel for non-cyclic */ + if (!edesc || (edesc && !edesc->cyclic)) + edma_pause(echan->ch_num); switch (ch_status) { case EDMA_DMA_COMPLETE: spin_lock_irqsave(&echan->vchan.lock, flags); - edesc = echan->edesc; if (edesc) { - if (edesc->processed == edesc->pset_nr) { + if (edesc->cyclic) { + vchan_cyclic_callback(&edesc->vdesc); + } else if (edesc->processed == edesc->pset_nr) { dev_dbg(dev, "Transfer complete, stopping channel %d\n", ch_num); edma_stop(echan->ch_num); vchan_cookie_complete(&edesc->vdesc); + edma_execute(echan); } else { dev_dbg(dev, "Intermediate transfer complete on channel %d\n", ch_num); + edma_execute(echan); } - - edma_execute(echan); } spin_unlock_irqrestore(&echan->vchan.lock, flags); @@ -680,6 +822,7 @@ static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma, struct device *dev) { dma->device_prep_slave_sg = edma_prep_slave_sg; + dma->device_prep_dma_cyclic = edma_prep_dma_cyclic; dma->device_alloc_chan_resources = edma_alloc_chan_resources; dma->device_free_chan_resources = edma_free_chan_resources; dma->device_issue_pending = edma_issue_pending; -- cgit v1.2.3 From b6d5050cccf6f5b664a9601f4a274175ed6ab0b4 Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Wed, 13 Nov 2013 12:06:24 +0530 Subject: dmaengine: edma: remove duplicate kfree fixing of freeing descriptor memory was applied twice, so remove the one duplicate Reported-by: Wing-Keung Wang Signed-off-by: Vinod Koul --- drivers/dma/edma.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/dma/edma.c') diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index 592f3be8b435..ab48430765b8 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -428,7 +428,6 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg( if (echan->slot[i] < 0) { kfree(edesc); dev_err(dev, "Failed to allocate slot\n"); - kfree(edesc); return NULL; } } -- cgit v1.2.3