[PATCH v2 1/2] dmaengine: fsl-edma: request per-channel IRQ only when channel is allocated

[PATCH v2 1/2] dmaengine: fsl-edma: request per-channel IRQ only when channel is allocated

[Frank Li]

The edma feature individual IRQs for each DMA channel at some devices.
Given the presence of numerous eDMA instances, each with multiple channels,
IRQ request during probe results in an extensive list at /proc/interrupts.
However, a significant portion of these channels remains unused by the
system.

Request irq only when a DMA client driver requests a DMA channel.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Notes:
    Change from v1 to v2
    - none

 drivers/dma/fsl-edma-common.c | 15 +++++++++++++++
 drivers/dma/fsl-edma-common.h |  1 +
 drivers/dma/fsl-edma-main.c   | 29 +++++++++++++++--------------
 3 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
index ac04a2ce4fa1f..91a4c11b7cbfd 100644
--- a/drivers/dma/fsl-edma-common.c
+++ b/drivers/dma/fsl-edma-common.c
@@ -805,6 +805,7 @@ void fsl_edma_issue_pending(struct dma_chan *chan)
 int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
 {
 	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+	int ret;
 
 	if (fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_HAS_CHCLK)
 		clk_prepare_enable(fsl_chan->clk);
@@ -813,6 +814,17 @@ int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
 				fsl_edma_drvflags(fsl_chan) & FSL_EDMA_DRV_TCD64 ?
 				sizeof(struct fsl_edma_hw_tcd64) : sizeof(struct fsl_edma_hw_tcd),
 				32, 0);
+
+	if (fsl_chan->txirq) {
+		ret = request_irq(fsl_chan->txirq, fsl_chan->irq_handler, IRQF_SHARED,
+				 fsl_chan->chan_name, fsl_chan);
+
+		if (ret) {
+			dma_pool_destroy(fsl_chan->tcd_pool);
+			return ret;
+		}
+	}
+
 	return 0;
 }
 
@@ -832,6 +844,9 @@ void fsl_edma_free_chan_resources(struct dma_chan *chan)
 	fsl_edma_unprep_slave_dma(fsl_chan);
 	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
 
+	if (fsl_chan->txirq)
+		free_irq(fsl_chan->txirq, fsl_chan);
+
 	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
 	dma_pool_destroy(fsl_chan->tcd_pool);
 	fsl_chan->tcd_pool = NULL;
diff --git a/drivers/dma/fsl-edma-common.h b/drivers/dma/fsl-edma-common.h
index dfbdcc922ceea..c5a766da02b88 100644
--- a/drivers/dma/fsl-edma-common.h
+++ b/drivers/dma/fsl-edma-common.h
@@ -172,6 +172,7 @@ struct fsl_edma_chan {
 	int                             priority;
 	int				hw_chanid;
 	int				txirq;
+	irqreturn_t			(*irq_handler)(int irq, void *dev_id);
 	bool				is_rxchan;
 	bool				is_remote;
 	bool				is_multi_fifo;
diff --git a/drivers/dma/fsl-edma-main.c b/drivers/dma/fsl-edma-main.c
index a1c3c4ed869c5..82ac56be2d832 100644
--- a/drivers/dma/fsl-edma-main.c
+++ b/drivers/dma/fsl-edma-main.c
@@ -65,6 +65,13 @@ static irqreturn_t fsl_edma3_tx_handler(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t fsl_edma2_tx_handler(int irq, void *devi_id)
+{
+	struct fsl_edma_chan *fsl_chan = devi_id;
+
+	return fsl_edma_tx_handler(irq, fsl_chan->edma);
+}
+
 static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
 {
 	struct fsl_edma_engine *fsl_edma = dev_id;
@@ -228,7 +235,6 @@ fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma
 
 static int fsl_edma3_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
 {
-	int ret;
 	int i;
 
 	for (i = 0; i < fsl_edma->n_chans; i++) {
@@ -243,13 +249,7 @@ static int fsl_edma3_irq_init(struct platform_device *pdev, struct fsl_edma_engi
 		if (fsl_chan->txirq < 0)
 			return  -EINVAL;
 
-		ret = devm_request_irq(&pdev->dev, fsl_chan->txirq,
-			fsl_edma3_tx_handler, IRQF_SHARED,
-			fsl_chan->chan_name, fsl_chan);
-		if (ret) {
-			dev_err(&pdev->dev, "Can't register chan%d's IRQ.\n", i);
-			return -EINVAL;
-		}
+		fsl_chan->irq_handler = fsl_edma3_tx_handler;
 	}
 
 	return 0;
@@ -278,19 +278,20 @@ fsl_edma2_irq_init(struct platform_device *pdev,
 	 */
 	for (i = 0; i < count; i++) {
 		irq = platform_get_irq(pdev, i);
+		ret = 0;
 		if (irq < 0)
 			return -ENXIO;
 
 		/* The last IRQ is for eDMA err */
-		if (i == count - 1)
+		if (i == count - 1) {
 			ret = devm_request_irq(&pdev->dev, irq,
 						fsl_edma_err_handler,
 						0, "eDMA2-ERR", fsl_edma);
-		else
-			ret = devm_request_irq(&pdev->dev, irq,
-						fsl_edma_tx_handler, 0,
-						fsl_edma->chans[i].chan_name,
-						fsl_edma);
+		} else {
+			fsl_edma->chans[i].txirq = irq;
+			fsl_edma->chans[i].irq_handler = fsl_edma2_tx_handler;
+		}
+
 		if (ret)
 			return ret;
 	}
-- 
2.34.1

[PATCH v2 2/2] dmaengine: fsl-edma: remove redundant "idle" field from fsl_chan

[Frank Li]

The 'idle' in fsl_chan is redundant as it's equivalent to
'status != DMA_IN_PROGRESS'. So remote it to simple code logic.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Notes:
    Change from v1 to v2
    Remove "idle" at mcf-edma-main.c also to build error found by
    | Reported-by: kernel test robot <lkp@intel.com>
    | Closes: https://lore.kernel.org/oe-kbuild-all/202406011344.s3sPp61I-lkp@intel.com/

 drivers/dma/fsl-edma-common.c | 6 +-----
 drivers/dma/fsl-edma-common.h | 2 --
 drivers/dma/fsl-edma-main.c   | 3 +--
 drivers/dma/mcf-edma-main.c   | 2 --
 4 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
index 91a4c11b7cbfd..e31dcc127708d 100644
--- a/drivers/dma/fsl-edma-common.c
+++ b/drivers/dma/fsl-edma-common.c
@@ -59,7 +59,6 @@ void fsl_edma_tx_chan_handler(struct fsl_edma_chan *fsl_chan)
 		vchan_cookie_complete(&fsl_chan->edesc->vdesc);
 		fsl_chan->edesc = NULL;
 		fsl_chan->status = DMA_COMPLETE;
-		fsl_chan->idle = true;
 	} else {
 		vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
 	}
@@ -239,7 +238,7 @@ int fsl_edma_terminate_all(struct dma_chan *chan)
 	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
 	fsl_edma_disable_request(fsl_chan);
 	fsl_chan->edesc = NULL;
-	fsl_chan->idle = true;
+	fsl_chan->status = DMA_COMPLETE;
 	vchan_get_all_descriptors(&fsl_chan->vchan, &head);
 	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
 	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
@@ -259,7 +258,6 @@ int fsl_edma_pause(struct dma_chan *chan)
 	if (fsl_chan->edesc) {
 		fsl_edma_disable_request(fsl_chan);
 		fsl_chan->status = DMA_PAUSED;
-		fsl_chan->idle = true;
 	}
 	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
 	return 0;
@@ -274,7 +272,6 @@ int fsl_edma_resume(struct dma_chan *chan)
 	if (fsl_chan->edesc) {
 		fsl_edma_enable_request(fsl_chan);
 		fsl_chan->status = DMA_IN_PROGRESS;
-		fsl_chan->idle = false;
 	}
 	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
 	return 0;
@@ -780,7 +777,6 @@ void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan)
 	fsl_edma_set_tcd_regs(fsl_chan, fsl_chan->edesc->tcd[0].vtcd);
 	fsl_edma_enable_request(fsl_chan);
 	fsl_chan->status = DMA_IN_PROGRESS;
-	fsl_chan->idle = false;
 }
 
 void fsl_edma_issue_pending(struct dma_chan *chan)
diff --git a/drivers/dma/fsl-edma-common.h b/drivers/dma/fsl-edma-common.h
index c5a766da02b88..b846cfe0a7fc6 100644
--- a/drivers/dma/fsl-edma-common.h
+++ b/drivers/dma/fsl-edma-common.h
@@ -150,7 +150,6 @@ struct fsl_edma_chan {
 	struct virt_dma_chan		vchan;
 	enum dma_status			status;
 	enum fsl_edma_pm_state		pm_state;
-	bool				idle;
 	struct fsl_edma_engine		*edma;
 	struct fsl_edma_desc		*edesc;
 	struct dma_slave_config		cfg;
@@ -456,7 +455,6 @@ static inline struct fsl_edma_desc *to_fsl_edma_desc(struct virt_dma_desc *vd)
 static inline void fsl_edma_err_chan_handler(struct fsl_edma_chan *fsl_chan)
 {
 	fsl_chan->status = DMA_ERROR;
-	fsl_chan->idle = true;
 }
 
 void fsl_edma_tx_chan_handler(struct fsl_edma_chan *fsl_chan);
diff --git a/drivers/dma/fsl-edma-main.c b/drivers/dma/fsl-edma-main.c
index 82ac56be2d832..af05166ed251f 100644
--- a/drivers/dma/fsl-edma-main.c
+++ b/drivers/dma/fsl-edma-main.c
@@ -544,7 +544,6 @@ static int fsl_edma_probe(struct platform_device *pdev)
 		fsl_chan->edma = fsl_edma;
 		fsl_chan->pm_state = RUNNING;
 		fsl_chan->srcid = 0;
-		fsl_chan->idle = true;
 		fsl_chan->dma_dir = DMA_NONE;
 		fsl_chan->vchan.desc_free = fsl_edma_free_desc;
 
@@ -669,7 +668,7 @@ static int fsl_edma_suspend_late(struct device *dev)
 			continue;
 		spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
 		/* Make sure chan is idle or will force disable. */
-		if (unlikely(!fsl_chan->idle)) {
+		if (unlikely(fsl_chan->status == DMA_IN_PROGRESS)) {
 			dev_warn(dev, "WARN: There is non-idle channel.");
 			fsl_edma_disable_request(fsl_chan);
 			fsl_edma_chan_mux(fsl_chan, 0, false);
diff --git a/drivers/dma/mcf-edma-main.c b/drivers/dma/mcf-edma-main.c
index d97991a1e9518..3ceb7b8f9a67d 100644
--- a/drivers/dma/mcf-edma-main.c
+++ b/drivers/dma/mcf-edma-main.c
@@ -64,7 +64,6 @@ static irqreturn_t mcf_edma_err_handler(int irq, void *dev_id)
 			fsl_edma_disable_request(&mcf_edma->chans[ch]);
 			iowrite8(EDMA_CERR_CERR(ch), regs->cerr);
 			mcf_edma->chans[ch].status = DMA_ERROR;
-			mcf_edma->chans[ch].idle = true;
 		}
 	}
 
@@ -196,7 +195,6 @@ static int mcf_edma_probe(struct platform_device *pdev)
 
 		mcf_chan->edma = mcf_edma;
 		mcf_chan->srcid = i;
-		mcf_chan->idle = true;
 		mcf_chan->dma_dir = DMA_NONE;
 		mcf_chan->vchan.desc_free = fsl_edma_free_desc;
 		vchan_init(&mcf_chan->vchan, &mcf_edma->dma_dev);
-- 
2.34.1

Re: [PATCH v2 1/2] dmaengine: fsl-edma: request per-channel IRQ only when channel is allocated

[Vinod Koul]

On Mon, 03 Jun 2024 11:23:15 -0400, Frank Li wrote:
> The edma feature individual IRQs for each DMA channel at some devices.
> Given the presence of numerous eDMA instances, each with multiple channels,
> IRQ request during probe results in an extensive list at /proc/interrupts.
> However, a significant portion of these channels remains unused by the
> system.
> 
> Request irq only when a DMA client driver requests a DMA channel.
> 
> [...]

Applied, thanks!

[1/2] dmaengine: fsl-edma: request per-channel IRQ only when channel is allocated
      commit: 44eb827264de4f14d8317692441e13f5e2aadbf2
[2/2] dmaengine: fsl-edma: remove redundant "idle" field from fsl_chan
      commit: bb160502a45440d2b52c189d5a81365c01b8d494

Best regards,
-- 
Vinod Koul <vkoul@kernel.org>