[PATCH v2 0/6] Fix some bugs and add new feature for Spreadtrum DMA engine

[PATCH v2 0/6] Fix some bugs and add new feature for Spreadtrum DMA engine

[Baolin Wang]

Hi,

This patch set fixes some DMA engine bugs and adds interrupt support
for 2-stage transfer.

Changes from v1:
 - Improve the commit message for patch 1.
 - Drop patch 4 from the v1 patch set, and I will create another patch
 set to move the fix to the core.

Baolin Wang (3):
  dmaengine: sprd: Fix the possible crash when getting descriptor
    status
  dmaengine: sprd: Add validation of current descriptor in irq handler
  dmaengine: sprd: Add interrupt support for 2-stage transfer

Eric Long (3):
  dmaengine: sprd: Fix the incorrect start for 2-stage destination
    channels
  dmaengine: sprd: Fix block length overflow
  dmaengine: sprd: Fix the right place to configure 2-stage transfer

 drivers/dma/sprd-dma.c |   49 +++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 38 insertions(+), 11 deletions(-)

-- 
1.7.9.5

[PATCH v2 1/6] dmaengine: sprd: Fix the possible crash when getting descriptor status

[Baolin Wang]

We will get a NULL virtual descriptor by vchan_find_desc() when the descriptor
has been submitted, that will crash the kernel when getting the descriptor
status.

In this case, since the descriptor has been submitted to process, but it
is not completed now, which means the descriptor is listed into the
'vc->desc_submitted' list now. So we can not get current processing descriptor
by vchan_find_desc(), but the pointer 'schan->cur_desc' will point to the
current processing descriptor, then we can use 'schan->cur_desc' to get
current processing descriptor's status to avoid this issue.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/dma/sprd-dma.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index 48431e2..e29342a 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -625,7 +625,7 @@ static enum dma_status sprd_dma_tx_status(struct dma_chan *chan,
 		else
 			pos = 0;
 	} else if (schan->cur_desc && schan->cur_desc->vd.tx.cookie == cookie) {
-		struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
+		struct sprd_dma_desc *sdesc = schan->cur_desc;
 
 		if (sdesc->dir == DMA_DEV_TO_MEM)
 			pos = sprd_dma_get_dst_addr(schan);
-- 
1.7.9.5

[PATCH v2 2/6] dmaengine: sprd: Add validation of current descriptor in irq handler

[Baolin Wang]

When user terminates one DMA channel to free all its descriptors, but
at the same time one transaction interrupt was triggered possibly, now
we should not handle this interrupt by validating if the 'schan->cur_desc'
was set as NULL to avoid crashing the kernel.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/dma/sprd-dma.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index e29342a..431e289 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -552,12 +552,17 @@ static irqreturn_t dma_irq_handle(int irq, void *dev_id)
 		schan = &sdev->channels[i];
 
 		spin_lock(&schan->vc.lock);
+
+		sdesc = schan->cur_desc;
+		if (!sdesc) {
+			spin_unlock(&schan->vc.lock);
+			return IRQ_HANDLED;
+		}
+
 		int_type = sprd_dma_get_int_type(schan);
 		req_type = sprd_dma_get_req_type(schan);
 		sprd_dma_clear_int(schan);
 
-		sdesc = schan->cur_desc;
-
 		/* cyclic mode schedule callback */
 		cyclic = schan->linklist.phy_addr ? true : false;
 		if (cyclic == true) {
-- 
1.7.9.5

[PATCH v2 3/6] dmaengine: sprd: Fix the incorrect start for 2-stage destination channels

[Baolin Wang]

From: Eric Long <eric.long@unisoc.com>

The 2-stage destination channel will be triggered by source channel
automatically, which means we should not trigger it by software request.

Signed-off-by: Eric Long <eric.long@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/dma/sprd-dma.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index 431e289..0f92e60 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -510,7 +510,9 @@ static void sprd_dma_start(struct sprd_dma_chn *schan)
 	sprd_dma_set_uid(schan);
 	sprd_dma_enable_chn(schan);
 
-	if (schan->dev_id == SPRD_DMA_SOFTWARE_UID)
+	if (schan->dev_id == SPRD_DMA_SOFTWARE_UID &&
+	    schan->chn_mode != SPRD_DMA_DST_CHN0 &&
+	    schan->chn_mode != SPRD_DMA_DST_CHN1)
 		sprd_dma_soft_request(schan);
 }
 
-- 
1.7.9.5

[PATCH v2 4/6] dmaengine: sprd: Fix block length overflow

[Baolin Wang]

From: Eric Long <eric.long@unisoc.com>

The maximum value of block length is 0xffff, so if the configured transfer length
is more than 0xffff, that will cause block length overflow to lead a configuration
error.

Thus we can set block length as the maximum burst length to avoid this issue, since
the maximum burst length will not be a big value which is more than 0xffff.

Signed-off-by: Eric Long <eric.long@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/dma/sprd-dma.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index 0f92e60..a01c232 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -778,7 +778,7 @@ static int sprd_dma_fill_desc(struct dma_chan *chan,
 	temp |= slave_cfg->src_maxburst & SPRD_DMA_FRG_LEN_MASK;
 	hw->frg_len = temp;
 
-	hw->blk_len = len & SPRD_DMA_BLK_LEN_MASK;
+	hw->blk_len = slave_cfg->src_maxburst & SPRD_DMA_BLK_LEN_MASK;
 	hw->trsc_len = len & SPRD_DMA_TRSC_LEN_MASK;
 
 	temp = (dst_step & SPRD_DMA_TRSF_STEP_MASK) << SPRD_DMA_DEST_TRSF_STEP_OFFSET;
-- 
1.7.9.5

[PATCH v2 5/6] dmaengine: sprd: Fix the right place to configure 2-stage transfer

[Baolin Wang]

From: Eric Long <eric.long@unisoc.com>

Move the 2-stage configuration before configuring the link-list mode,
since we will use some 2-stage configuration to fill the link-list
configuration.

Signed-off-by: Eric Long <eric.long@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/dma/sprd-dma.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index a01c232..01abed5 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -911,6 +911,12 @@ static int sprd_dma_fill_linklist_desc(struct dma_chan *chan,
 		schan->linklist.virt_addr = 0;
 	}
 
+	/* Set channel mode and trigger mode for 2-stage transfer */
+	schan->chn_mode =
+		(flags >> SPRD_DMA_CHN_MODE_SHIFT) & SPRD_DMA_CHN_MODE_MASK;
+	schan->trg_mode =
+		(flags >> SPRD_DMA_TRG_MODE_SHIFT) & SPRD_DMA_TRG_MODE_MASK;
+
 	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
 	if (!sdesc)
 		return NULL;
@@ -944,12 +950,6 @@ static int sprd_dma_fill_linklist_desc(struct dma_chan *chan,
 		}
 	}
 
-	/* Set channel mode and trigger mode for 2-stage transfer */
-	schan->chn_mode =
-		(flags >> SPRD_DMA_CHN_MODE_SHIFT) & SPRD_DMA_CHN_MODE_MASK;
-	schan->trg_mode =
-		(flags >> SPRD_DMA_TRG_MODE_SHIFT) & SPRD_DMA_TRG_MODE_MASK;
-
 	ret = sprd_dma_fill_desc(chan, &sdesc->chn_hw, 0, 0, src, dst, len,
 				 dir, flags, slave_cfg);
 	if (ret) {
-- 
1.7.9.5

[PATCH v2 6/6] dmaengine: sprd: Add interrupt support for 2-stage transfer

[Baolin Wang]

For 2-stage transfer, some users like Audio still need transaction interrupt
to notify when the 2-stage transfer is completed. Thus we should enable
2-stage transfer interrupt to support this feature.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/dma/sprd-dma.c |   22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
index 01abed5..baac476 100644
--- a/drivers/dma/sprd-dma.c
+++ b/drivers/dma/sprd-dma.c
@@ -62,6 +62,8 @@
 /* SPRD_DMA_GLB_2STAGE_GRP register definition */
 #define SPRD_DMA_GLB_2STAGE_EN		BIT(24)
 #define SPRD_DMA_GLB_CHN_INT_MASK	GENMASK(23, 20)
+#define SPRD_DMA_GLB_DEST_INT		BIT(22)
+#define SPRD_DMA_GLB_SRC_INT		BIT(20)
 #define SPRD_DMA_GLB_LIST_DONE_TRG	BIT(19)
 #define SPRD_DMA_GLB_TRANS_DONE_TRG	BIT(18)
 #define SPRD_DMA_GLB_BLOCK_DONE_TRG	BIT(17)
@@ -135,6 +137,7 @@
 /* define DMA channel mode & trigger mode mask */
 #define SPRD_DMA_CHN_MODE_MASK		GENMASK(7, 0)
 #define SPRD_DMA_TRG_MODE_MASK		GENMASK(7, 0)
+#define SPRD_DMA_INT_TYPE_MASK		GENMASK(7, 0)
 
 /* define the DMA transfer step type */
 #define SPRD_DMA_NONE_STEP		0
@@ -190,6 +193,7 @@ struct sprd_dma_chn {
 	u32			dev_id;
 	enum sprd_dma_chn_mode	chn_mode;
 	enum sprd_dma_trg_mode	trg_mode;
+	enum sprd_dma_int_type	int_type;
 	struct sprd_dma_desc	*cur_desc;
 };
 
@@ -429,6 +433,9 @@ static int sprd_dma_set_2stage_config(struct sprd_dma_chn *schan)
 		val = chn & SPRD_DMA_GLB_SRC_CHN_MASK;
 		val |= BIT(schan->trg_mode - 1) << SPRD_DMA_GLB_TRG_OFFSET;
 		val |= SPRD_DMA_GLB_2STAGE_EN;
+		if (schan->int_type != SPRD_DMA_NO_INT)
+			val |= SPRD_DMA_GLB_SRC_INT;
+
 		sprd_dma_glb_update(sdev, SPRD_DMA_GLB_2STAGE_GRP1, val, val);
 		break;
 
@@ -436,6 +443,9 @@ static int sprd_dma_set_2stage_config(struct sprd_dma_chn *schan)
 		val = chn & SPRD_DMA_GLB_SRC_CHN_MASK;
 		val |= BIT(schan->trg_mode - 1) << SPRD_DMA_GLB_TRG_OFFSET;
 		val |= SPRD_DMA_GLB_2STAGE_EN;
+		if (schan->int_type != SPRD_DMA_NO_INT)
+			val |= SPRD_DMA_GLB_SRC_INT;
+
 		sprd_dma_glb_update(sdev, SPRD_DMA_GLB_2STAGE_GRP2, val, val);
 		break;
 
@@ -443,6 +453,9 @@ static int sprd_dma_set_2stage_config(struct sprd_dma_chn *schan)
 		val = (chn << SPRD_DMA_GLB_DEST_CHN_OFFSET) &
 			SPRD_DMA_GLB_DEST_CHN_MASK;
 		val |= SPRD_DMA_GLB_2STAGE_EN;
+		if (schan->int_type != SPRD_DMA_NO_INT)
+			val |= SPRD_DMA_GLB_DEST_INT;
+
 		sprd_dma_glb_update(sdev, SPRD_DMA_GLB_2STAGE_GRP1, val, val);
 		break;
 
@@ -450,6 +463,9 @@ static int sprd_dma_set_2stage_config(struct sprd_dma_chn *schan)
 		val = (chn << SPRD_DMA_GLB_DEST_CHN_OFFSET) &
 			SPRD_DMA_GLB_DEST_CHN_MASK;
 		val |= SPRD_DMA_GLB_2STAGE_EN;
+		if (schan->int_type != SPRD_DMA_NO_INT)
+			val |= SPRD_DMA_GLB_DEST_INT;
+
 		sprd_dma_glb_update(sdev, SPRD_DMA_GLB_2STAGE_GRP2, val, val);
 		break;
 
@@ -911,11 +927,15 @@ static int sprd_dma_fill_linklist_desc(struct dma_chan *chan,
 		schan->linklist.virt_addr = 0;
 	}
 
-	/* Set channel mode and trigger mode for 2-stage transfer */
+	/*
+	 * Set channel mode, interrupt mode and trigger mode for 2-stage
+	 * transfer.
+	 */
 	schan->chn_mode =
 		(flags >> SPRD_DMA_CHN_MODE_SHIFT) & SPRD_DMA_CHN_MODE_MASK;
 	schan->trg_mode =
 		(flags >> SPRD_DMA_TRG_MODE_SHIFT) & SPRD_DMA_TRG_MODE_MASK;
+	schan->int_type = flags & SPRD_DMA_INT_TYPE_MASK;
 
 	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
 	if (!sdesc)
-- 
1.7.9.5

Re: [PATCH v2 0/6] Fix some bugs and add new feature for Spreadtrum DMA engine

[Vinod Koul]

On 06-05-19, 15:28, Baolin Wang wrote:
> Hi,
> 
> This patch set fixes some DMA engine bugs and adds interrupt support
> for 2-stage transfer.

Applied all, thanks
-- 
~Vinod