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[PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line

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  [PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line Robert Jarzmik <robert.jarzmik@free.fr> - 2016-02-11 22:30 +0100
    Re: [PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line Vinod Koul <vinod.koul@intel.com> - 2016-02-15 17:40 +0100
      Re: [PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line Vinod Koul <vinod.koul@intel.com> - 2016-02-15 18:30 +0100
        Re: [PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line Robert Jarzmik <robert.jarzmik@free.fr> - 2016-02-15 19:30 +0100
      Re: [PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line Robert Jarzmik <robert.jarzmik@free.fr> - 2016-02-15 18:30 +0100

#1332380 — [PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line

The current number of requestor lines is limited to 31. This was an
error of a previous commit, as this number is platform dependent, and is
actually :
 - for pxa25x: 40 requestor lines
 - for pxa27x: 75 requestor lines
 - for pxa3xx: 100 requestor lines

The previous testing did not reveal the faulty constant as on pxa[23]xx
platforms, only camera, MSL and USB are above requestor 32, and in these
only the camera has a driver using dma.

Fixes: e87ffbdf0697 ("dmaengine: pxa_dma: fix the no-requestor case")
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
---
 drivers/dma/pxa_dma.c | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c
index ca6c088edc8a..bc51d6271373 100644
--- a/drivers/dma/pxa_dma.c
+++ b/drivers/dma/pxa_dma.c
@@ -122,6 +122,7 @@ struct pxad_chan {
 struct pxad_device {
 	struct dma_device		slave;
 	int				nr_chans;
+	int				nr_requestors;
 	void __iomem			*base;
 	struct pxad_phy			*phys;
 	spinlock_t			phy_lock;	/* Phy association */
@@ -473,7 +474,7 @@ static void pxad_free_phy(struct pxad_chan *chan)
 		return;
 
 	/* clear the channel mapping in DRCMR */
-	if (chan->drcmr <= DRCMR_CHLNUM) {
+	if (chan->drcmr <= pdev->nr_requestors) {
 		reg = pxad_drcmr(chan->drcmr);
 		writel_relaxed(0, chan->phy->base + reg);
 	}
@@ -509,6 +510,7 @@ static bool is_running_chan_misaligned(struct pxad_chan *chan)
 
 static void phy_enable(struct pxad_phy *phy, bool misaligned)
 {
+	struct pxad_device *pdev;
 	u32 reg, dalgn;
 
 	if (!phy->vchan)
@@ -518,7 +520,8 @@ static void phy_enable(struct pxad_phy *phy, bool misaligned)
 		"%s(); phy=%p(%d) misaligned=%d\n", __func__,
 		phy, phy->idx, misaligned);
 
-	if (phy->vchan->drcmr <= DRCMR_CHLNUM) {
+	pdev = to_pxad_dev(phy->vchan->vc.chan.device);
+	if (phy->vchan->drcmr <= pdev->nr_requestors) {
 		reg = pxad_drcmr(phy->vchan->drcmr);
 		writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg);
 	}
@@ -914,6 +917,7 @@ static void pxad_get_config(struct pxad_chan *chan,
 {
 	u32 maxburst = 0, dev_addr = 0;
 	enum dma_slave_buswidth width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
+	struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device);
 
 	*dcmd = 0;
 	if (dir == DMA_DEV_TO_MEM) {
@@ -922,7 +926,7 @@ static void pxad_get_config(struct pxad_chan *chan,
 		dev_addr = chan->cfg.src_addr;
 		*dev_src = dev_addr;
 		*dcmd |= PXA_DCMD_INCTRGADDR;
-		if (chan->drcmr <= DRCMR_CHLNUM)
+		if (chan->drcmr <= pdev->nr_requestors)
 			*dcmd |= PXA_DCMD_FLOWSRC;
 	}
 	if (dir == DMA_MEM_TO_DEV) {
@@ -931,7 +935,7 @@ static void pxad_get_config(struct pxad_chan *chan,
 		dev_addr = chan->cfg.dst_addr;
 		*dev_dst = dev_addr;
 		*dcmd |= PXA_DCMD_INCSRCADDR;
-		if (chan->drcmr <= DRCMR_CHLNUM)
+		if (chan->drcmr <= pdev->nr_requestors)
 			*dcmd |= PXA_DCMD_FLOWTRG;
 	}
 	if (dir == DMA_MEM_TO_MEM)
@@ -1341,13 +1345,15 @@ static struct dma_chan *pxad_dma_xlate(struct of_phandle_args *dma_spec,
 
 static int pxad_init_dmadev(struct platform_device *op,
 			    struct pxad_device *pdev,
-			    unsigned int nr_phy_chans)
+			    unsigned int nr_phy_chans,
+			    unsigned int nr_requestors)
 {
 	int ret;
 	unsigned int i;
 	struct pxad_chan *c;
 
 	pdev->nr_chans = nr_phy_chans;
+	pdev->nr_requestors = nr_requestors;
 	INIT_LIST_HEAD(&pdev->slave.channels);
 	pdev->slave.device_alloc_chan_resources = pxad_alloc_chan_resources;
 	pdev->slave.device_free_chan_resources = pxad_free_chan_resources;
@@ -1382,7 +1388,7 @@ static int pxad_probe(struct platform_device *op)
 	const struct of_device_id *of_id;
 	struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
 	struct resource *iores;
-	int ret, dma_channels = 0;
+	int ret, dma_channels = 0, nb_requestors = 0;
 	const enum dma_slave_buswidth widths =
 		DMA_SLAVE_BUSWIDTH_1_BYTE   | DMA_SLAVE_BUSWIDTH_2_BYTES |
 		DMA_SLAVE_BUSWIDTH_4_BYTES;
@@ -1399,13 +1405,17 @@ static int pxad_probe(struct platform_device *op)
 		return PTR_ERR(pdev->base);
 
 	of_id = of_match_device(pxad_dt_ids, &op->dev);
-	if (of_id)
+	if (of_id) {
 		of_property_read_u32(op->dev.of_node, "#dma-channels",
 				     &dma_channels);
-	else if (pdata && pdata->dma_channels)
+		of_property_read_u32(op->dev.of_node, "#requestors",
+				     &nb_requestors);
+	} else if (pdata && pdata->dma_channels) {
 		dma_channels = pdata->dma_channels;
-	else
+		nb_requestors = pdata->nb_requestors;
+	} else {
 		dma_channels = 32;	/* default 32 channel */
+	}
 
 	dma_cap_set(DMA_SLAVE, pdev->slave.cap_mask);
 	dma_cap_set(DMA_MEMCPY, pdev->slave.cap_mask);
@@ -1423,7 +1433,7 @@ static int pxad_probe(struct platform_device *op)
 	pdev->slave.descriptor_reuse = true;
 
 	pdev->slave.dev = &op->dev;
-	ret = pxad_init_dmadev(op, pdev, dma_channels);
+	ret = pxad_init_dmadev(op, pdev, dma_channels, nb_requestors);
 	if (ret) {
 		dev_err(pdev->slave.dev, "unable to register\n");
 		return ret;
@@ -1442,7 +1452,8 @@ static int pxad_probe(struct platform_device *op)
 
 	platform_set_drvdata(op, pdev);
 	pxad_init_debugfs(pdev);
-	dev_info(pdev->slave.dev, "initialized %d channels\n", dma_channels);
+	dev_info(pdev->slave.dev, "initialized %d channels on %d requestors\n",
+		 dma_channels, nb_requestors);
 	return 0;
 }
 
-- 
2.1.4

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#1334580

On Thu, Feb 11, 2016 at 10:23:18PM +0100, Robert Jarzmik wrote:
> @@ -1399,13 +1405,17 @@ static int pxad_probe(struct platform_device *op)
>  		return PTR_ERR(pdev->base);
>  
>  	of_id = of_match_device(pxad_dt_ids, &op->dev);
> -	if (of_id)
> +	if (of_id) {
>  		of_property_read_u32(op->dev.of_node, "#dma-channels",
>  				     &dma_channels);
> -	else if (pdata && pdata->dma_channels)
> +		of_property_read_u32(op->dev.of_node, "#requestors",
> +				     &nb_requestors);

I think we should check the return value here. This might be err in case
when we have older DT on platform, but still should work with default in
that case

> +	} else if (pdata && pdata->dma_channels) {
>  		dma_channels = pdata->dma_channels;
> -	else
> +		nb_requestors = pdata->nb_requestors;
> +	} else {
>  		dma_channels = 32;	/* default 32 channel */
> +	}

-- 
~Vinod

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#1334644

On Mon, Feb 15, 2016 at 06:24:57PM +0100, Robert Jarzmik wrote:
> Vinod Koul <vinod.koul@intel.com> writes:
> 
> > On Thu, Feb 11, 2016 at 10:23:18PM +0100, Robert Jarzmik wrote:
> >> @@ -1399,13 +1405,17 @@ static int pxad_probe(struct platform_device *op)
> >>  		return PTR_ERR(pdev->base);
> >>  
> >>  	of_id = of_match_device(pxad_dt_ids, &op->dev);
> >> -	if (of_id)
> >> +	if (of_id) {
> >>  		of_property_read_u32(op->dev.of_node, "#dma-channels",
> >>  				     &dma_channels);
> >> -	else if (pdata && pdata->dma_channels)
> >> +		of_property_read_u32(op->dev.of_node, "#requestors",
> >> +				     &nb_requestors);
> >
> > I think we should check the return value here. This might be err in case
> > when we have older DT on platform, but still should work with default in
> > that case
> 
> Okay, but how should the code react to the err case, more specifically to
> -EINVAL or -ENODATA ? As this property is optional as per the device-tree
> description, the current code leaves nb_requestors = 0, as is specified in the
> description, and fits the mmp_pdma case.
> 
> What do you think should be done ? A warning message ? Something else ?

Message is fine, but in order for not to regress we should set this to 32
(IIRC default before this, right) and not zero.

-- 
~Vinod

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#1334703

Vinod Koul <vinod.koul@intel.com> writes:

> On Mon, Feb 15, 2016 at 06:24:57PM +0100, Robert Jarzmik wrote:
>> Vinod Koul <vinod.koul@intel.com> writes:
>> 
>> > On Thu, Feb 11, 2016 at 10:23:18PM +0100, Robert Jarzmik wrote:
>> >> @@ -1399,13 +1405,17 @@ static int pxad_probe(struct platform_device *op)
>> >>  		return PTR_ERR(pdev->base);
>> >>  
>> >>  	of_id = of_match_device(pxad_dt_ids, &op->dev);
>> >> -	if (of_id)
>> >> +	if (of_id) {
>> >>  		of_property_read_u32(op->dev.of_node, "#dma-channels",
>> >>  				     &dma_channels);
>> >> -	else if (pdata && pdata->dma_channels)
>> >> +		of_property_read_u32(op->dev.of_node, "#requestors",
>> >> +				     &nb_requestors);
>> >
>> > I think we should check the return value here. This might be err in case
>> > when we have older DT on platform, but still should work with default in
>> > that case
>> 
>> Okay, but how should the code react to the err case, more specifically to
>> -EINVAL or -ENODATA ? As this property is optional as per the device-tree
>> description, the current code leaves nb_requestors = 0, as is specified in the
>> description, and fits the mmp_pdma case.
>> 
>> What do you think should be done ? A warning message ? Something else ?
>
> Message is fine, but in order for not to regress we should set this to 32
> (IIRC default before this, right) and not zero.
Okay, got you.

For v2 I'll implement exactly this, ie. a warning message and a default to 32.
I'll amend the device-tree description also to match the 32 (and not the 0 I
wrote earlier).

Cheers.

-- 
Robert

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#1334648

Vinod Koul <vinod.koul@intel.com> writes:

> On Thu, Feb 11, 2016 at 10:23:18PM +0100, Robert Jarzmik wrote:
>> @@ -1399,13 +1405,17 @@ static int pxad_probe(struct platform_device *op)
>>  		return PTR_ERR(pdev->base);
>>  
>>  	of_id = of_match_device(pxad_dt_ids, &op->dev);
>> -	if (of_id)
>> +	if (of_id) {
>>  		of_property_read_u32(op->dev.of_node, "#dma-channels",
>>  				     &dma_channels);
>> -	else if (pdata && pdata->dma_channels)
>> +		of_property_read_u32(op->dev.of_node, "#requestors",
>> +				     &nb_requestors);
>
> I think we should check the return value here. This might be err in case
> when we have older DT on platform, but still should work with default in
> that case

Okay, but how should the code react to the err case, more specifically to
-EINVAL or -ENODATA ? As this property is optional as per the device-tree
description, the current code leaves nb_requestors = 0, as is specified in the
description, and fits the mmp_pdma case.

What do you think should be done ? A warning message ? Something else ?

Cheers.

--
Robert

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