From 1f9cd915b64bb95f7b41667b4bf8b22f0a0a557b Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 11 Nov 2014 19:35:52 +0100 Subject: dmaengine: sun6i: Fix memcpy operation The prep_memcpy call was not setting any meaningful burst and width because it was relying on the dma_slave_config was not set already. Rework the needed conversion functions, and hardcode the width and burst to use. Signed-off-by: Maxime Ripard Cc: stable@vger.kernel.org Signed-off-by: Vinod Koul --- drivers/dma/sun6i-dma.c | 61 ++++++++++++++++++++++++------------------------- 1 file changed, 30 insertions(+), 31 deletions(-) (limited to 'drivers') diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index 3aa10b328254..91292f5513ff 100644 --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -230,30 +230,25 @@ static inline void sun6i_dma_dump_chan_regs(struct sun6i_dma_dev *sdev, readl(pchan->base + DMA_CHAN_CUR_PARA)); } -static inline int convert_burst(u32 maxburst, u8 *burst) +static inline s8 convert_burst(u32 maxburst) { switch (maxburst) { case 1: - *burst = 0; - break; + return 0; case 8: - *burst = 2; - break; + return 2; default: return -EINVAL; } - - return 0; } -static inline int convert_buswidth(enum dma_slave_buswidth addr_width, u8 *width) +static inline s8 convert_buswidth(enum dma_slave_buswidth addr_width) { if ((addr_width < DMA_SLAVE_BUSWIDTH_1_BYTE) || (addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES)) return -EINVAL; - *width = addr_width >> 1; - return 0; + return addr_width >> 1; } static void *sun6i_dma_lli_add(struct sun6i_dma_lli *prev, @@ -284,26 +279,25 @@ static inline int sun6i_dma_cfg_lli(struct sun6i_dma_lli *lli, struct dma_slave_config *config) { u8 src_width, dst_width, src_burst, dst_burst; - int ret; if (!config) return -EINVAL; - ret = convert_burst(config->src_maxburst, &src_burst); - if (ret) - return ret; + src_burst = convert_burst(config->src_maxburst); + if (src_burst) + return src_burst; - ret = convert_burst(config->dst_maxburst, &dst_burst); - if (ret) - return ret; + dst_burst = convert_burst(config->dst_maxburst); + if (dst_burst) + return dst_burst; - ret = convert_buswidth(config->src_addr_width, &src_width); - if (ret) - return ret; + src_width = convert_buswidth(config->src_addr_width); + if (src_width) + return src_width; - ret = convert_buswidth(config->dst_addr_width, &dst_width); - if (ret) - return ret; + dst_width = convert_buswidth(config->dst_addr_width); + if (dst_width) + return dst_width; lli->cfg = DMA_CHAN_CFG_SRC_BURST(src_burst) | DMA_CHAN_CFG_SRC_WIDTH(src_width) | @@ -542,11 +536,10 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy( { struct sun6i_dma_dev *sdev = to_sun6i_dma_dev(chan->device); struct sun6i_vchan *vchan = to_sun6i_vchan(chan); - struct dma_slave_config *sconfig = &vchan->cfg; struct sun6i_dma_lli *v_lli; struct sun6i_desc *txd; dma_addr_t p_lli; - int ret; + s8 burst, width; dev_dbg(chan2dev(chan), "%s; chan: %d, dest: %pad, src: %pad, len: %zu. flags: 0x%08lx\n", @@ -565,14 +558,21 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy( goto err_txd_free; } - ret = sun6i_dma_cfg_lli(v_lli, src, dest, len, sconfig); - if (ret) - goto err_dma_free; + v_lli->src = src; + v_lli->dst = dest; + v_lli->len = len; + v_lli->para = NORMAL_WAIT; + burst = convert_burst(8); + width = convert_buswidth(DMA_SLAVE_BUSWIDTH_4_BYTES); v_lli->cfg |= DMA_CHAN_CFG_SRC_DRQ(DRQ_SDRAM) | DMA_CHAN_CFG_DST_DRQ(DRQ_SDRAM) | DMA_CHAN_CFG_DST_LINEAR_MODE | - DMA_CHAN_CFG_SRC_LINEAR_MODE; + DMA_CHAN_CFG_SRC_LINEAR_MODE | + DMA_CHAN_CFG_SRC_BURST(burst) | + DMA_CHAN_CFG_SRC_WIDTH(width) | + DMA_CHAN_CFG_DST_BURST(burst) | + DMA_CHAN_CFG_DST_WIDTH(width); sun6i_dma_lli_add(NULL, v_lli, p_lli, txd); @@ -580,8 +580,6 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy( return vchan_tx_prep(&vchan->vc, &txd->vd, flags); -err_dma_free: - dma_pool_free(sdev->pool, v_lli, p_lli); err_txd_free: kfree(txd); return NULL; @@ -915,6 +913,7 @@ static int sun6i_dma_probe(struct platform_device *pdev) sdc->slave.device_prep_dma_memcpy = sun6i_dma_prep_dma_memcpy; sdc->slave.device_control = sun6i_dma_control; sdc->slave.chancnt = NR_MAX_VCHANS; + sdc->slave.copy_align = 4; sdc->slave.dev = &pdev->dev; -- cgit v1.2.3 From 137bd11090d89b3a3ef4bdb7a6cf964ffc797517 Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Fri, 7 Nov 2014 18:05:17 +0000 Subject: dmaengine: pl330: Align DMA memcpy operations to MFIFO width The algorithm used for programming the DMA Controller doesn't take into consideration the requirements of transfers that are not aligned to the bus width. This failure may result in DMA transferring one too few MFIFO entries (so too few bytes are copied) or the DMA trying to write one too many MFIFO entries and hanging because this is never provided. See "MFIFO Usage Overview" chapter in the the TRM for "CoreLink DMA Controller DMA-330", Revision r1p1. We work around these shortcomings by making sure we pick a burst size and length which ensures no bursts straddle an MFIFO entry. Signed-off-by: Jon Medhurst [squashed linker error "undefined reference to `__aeabi_uldivmod] Reported-by: kbuild test robot Acked-by: Arnd Bergmann Signed-off-by: Vinod Koul --- drivers/dma/pl330.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 4839bfa74a10..81505420bde4 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2459,16 +2459,25 @@ pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst, /* Select max possible burst size */ burst = pl330->pcfg.data_bus_width / 8; - while (burst > 1) { - if (!(len % burst)) - break; + /* + * Make sure we use a burst size that aligns with all the memcpy + * parameters because our DMA programming algorithm doesn't cope with + * transfers which straddle an entry in the DMA device's MFIFO. + */ + while ((src | dst | len) & (burst - 1)) burst /= 2; - } desc->rqcfg.brst_size = 0; while (burst != (1 << desc->rqcfg.brst_size)) desc->rqcfg.brst_size++; + /* + * If burst size is smaller than bus width then make sure we only + * transfer one at a time to avoid a burst stradling an MFIFO entry. + */ + if (desc->rqcfg.brst_size * 8 < pl330->pcfg.data_bus_width) + desc->rqcfg.brst_len = 1; + desc->rqcfg.brst_len = get_burst_len(desc, len); desc->txd.flags = flags; -- cgit v1.2.3 From c27f95568d1ed2573fc9c8848d741da63ca9a34e Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Fri, 7 Nov 2014 18:05:18 +0000 Subject: dmaengine: pl330: Limit MFIFO usage for memcpy to avoid exhausting entries The MFIFO is shared by all channels so restrict each memcpy to it's fair share. This is being over cautious, but without a global view of DMA channel usage on a system it's not possible to come up with a more optimum safe limit. Signed-off-by: Jon Medhurst Signed-off-by: Vinod Koul --- drivers/dma/pl330.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 81505420bde4..e13b51a46502 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2336,7 +2336,7 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len) int burst_len; burst_len = pl330->pcfg.data_bus_width / 8; - burst_len *= pl330->pcfg.data_buf_dep; + burst_len *= pl330->pcfg.data_buf_dep / pl330->pcfg.num_chan; burst_len >>= desc->rqcfg.brst_size; /* src/dst_burst_len can't be more than 16 */ -- cgit v1.2.3 From 1f0a5cbf61a54504236bbbe2c98b58e85f90e650 Mon Sep 17 00:00:00 2001 From: Liviu Dudau Date: Thu, 6 Nov 2014 17:20:12 +0000 Subject: dmaengine: Fix allocation size for PL330 data buffer depth. The datasheet for PL330 says that the data buffer value in the CRD register is 10bits wide. However, the value stored is "minus one", which the driver corrects for. Maximum value that the data buffer depth can have is 1024 lines, which requires 11 bits for storage. While making updates I found printing the peripheral ID as a hex value to be more useful as the datasheet shows the values that way. Signed-off-by: Liviu Dudau Signed-off-by: Vinod Koul --- drivers/dma/pl330.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index e13b51a46502..19a99743cf52 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -271,7 +271,7 @@ struct pl330_config { #define DMAC_MODE_NS (1 << 0) unsigned int mode; unsigned int data_bus_width:10; /* In number of bits */ - unsigned int data_buf_dep:10; + unsigned int data_buf_dep:11; unsigned int num_chan:4; unsigned int num_peri:6; u32 peri_ns; @@ -2741,7 +2741,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id) dev_info(&adev->dev, - "Loaded driver for PL330 DMAC-%d\n", adev->periphid); + "Loaded driver for PL330 DMAC-%x\n", adev->periphid); dev_info(&adev->dev, "\tDBUFF-%ux%ubytes Num_Chans-%u Num_Peri-%u Num_Events-%u\n", pcfg->data_buf_dep, pcfg->data_bus_width / 8, pcfg->num_chan, -- cgit v1.2.3