-----Original Message-----
From: Robin Murphy [mailto:robin.murphy at arm.com]
Sent: Tuesday, July 3, 2018 9:44 PM
To: Nipun Gupta <redacted>; will.deacon at arm.com;
robh+dt at kernel.org; robh at kernel.org; mark.rutland at arm.com;
catalin.marinas at arm.com; gregkh at linuxfoundation.org; Laurentiu Tudor
[off-list ref]; bhelgaas at google.com
Cc: hch at lst.de; joro at 8bytes.org; m.szyprowski at samsung.com;
shawnguo at kernel.org; frowand.list at gmail.com; iommu at lists.linux-
foundation.org; linux-kernel at vger.kernel.org; devicetree at vger.kernel.org;
linux-arm-kernel at lists.infradead.org; linuxppc-dev at lists.ozlabs.org; linux-
pci at vger.kernel.org; Bharat Bhushan [off-list ref];
stuyoder at gmail.com; Leo Li [off-list ref]
Subject: Re: [PATCH 5/7 v5] bus: fsl-mc: support dma configure for devices
on fsl-mc bus

On 20/05/18 14:49, Nipun Gupta wrote:

quoted

This patch adds support of dma configuration for devices on fsl-mc
bus using 'dma_configure' callback for busses. Also, directly calling
arch_setup_dma_ops is removed from the fsl-mc bus.

Looks like this is the final arch_setup_dma_ops offender, yay!

quoted

Signed-off-by: Nipun Gupta <redacted>
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
---
  drivers/bus/fsl-mc/fsl-mc-bus.c | 15 +++++++++++----
  1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-

bus.c

quoted

index 5d8266c..fa43c7d 100644

--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c

@@ -127,6 +127,16 @@ static int fsl_mc_bus_uevent(struct device *dev,

struct kobj_uevent_env *env)

quoted

  	return 0;
  }

+static int fsl_mc_dma_configure(struct device *dev)
+{
+	struct device *dma_dev = dev;
+
+	while (dev_is_fsl_mc(dma_dev))
+		dma_dev = dma_dev->parent;
+
+	return of_dma_configure(dev, dma_dev->of_node, 0);
+}
+
  static ssize_t modalias_show(struct device *dev, struct device_attribute

*attr,

quoted

  			     char *buf)
  {

@@ -148,6 +158,7 @@ struct bus_type fsl_mc_bus_type = {
  	.name = "fsl-mc",
  	.match = fsl_mc_bus_match,
  	.uevent = fsl_mc_bus_uevent,
+	.dma_configure  = fsl_mc_dma_configure,
  	.dev_groups = fsl_mc_dev_groups,
  };
  EXPORT_SYMBOL_GPL(fsl_mc_bus_type);

@@ -633,10 +644,6 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc

*obj_desc,

quoted

  			goto error_cleanup_dev;
  	}

-	/* Objects are coherent, unless 'no shareability' flag set. */
-	if (!(obj_desc->flags &

FSL_MC_OBJ_FLAG_NO_MEM_SHAREABILITY))

Although it seems we do end up without any handling of this
"non-coherent object behind coherent MC" case, and I'm not sure how
easily that could be accommodated by generic code... :/ How important is
the quirk?

We have all the devices as coherent in our SoC's now :) So this is fine.
We have internally discussed it.

Regards,
Nipun

Robin.

quoted

-		arch_setup_dma_ops(&mc_dev->dev, 0, 0, NULL, true);
-
  	/*
  	 * The device-specific probe callback will get invoked by device_add()
  	 */