Re: [RFC PATCH v2 05/11] ACPI: platform: setup MSI domain for ACPI based platform device

From: Hanjun Guo
Date: Mon Sep 19 2016 - 05:42:53 EST

On 2016/9/15 23:18, Marc Zyngier wrote:
On 15/09/16 15:05, Hanjun Guo wrote:
Hi Marc,
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 6482d47..ea01a37 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -24,6 +24,7 @@
#include <linux/pm_domain.h>
#include <linux/idr.h>
#include <linux/acpi.h>
+#include <linux/msi.h>
#include <linux/clk/clk-conf.h>
#include <linux/limits.h>
#include <linux/property.h>
@@ -500,6 +501,7 @@ struct platform_device *platform_device_register_full(
pdev->dev.parent = pdevinfo->parent;
pdev->dev.fwnode = pdevinfo->fwnode;

+ acpi_configure_msi_domain(&pdev->dev);

It feels odd to put this in the generic code, while you could perfectly
put the call into acpi_platform.c and keep the firmware stuff away from
the generic code.

My feeling is the same, I'm still trying to find a new way to do it,
but I can't simply put that in acpi_platform.c, because

platform_device_alloc() --> dev is alloced
dev.fwnode is set
(I get the msi domain by the fwnode in acpi_configure_msi_domain)
platform_device_add() --> which the device is probed.

For devices like irqchip which needs the dev->msi_domain to be
set before it's really probed, because it needs the msi domain
to be the parent domain.

If I call the function in acpi_create_platform_device() before
platform_device_register_full(), we just can't set dev's msi
domain, but if call it after platform_device_register_full(),
the irqchip like mbigen will not get its parent domain...

DT is using another API for platform device probe, so has no
problems like I said above, any suggestions to do it right in

How about having something that's completely generic and solves
the problem once and for all? Something like this:

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 6482d47..6f0f90b 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -533,6 +533,9 @@ struct platform_device *platform_device_register_full(
goto err;

+ if (pdevinfo->pre_add_cb)
+ pdevinfo->pre_add_cb(&pdev->dev);
ret = platform_device_add(pdev);
if (ret) {
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 98c2a7c..44ea133 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -74,6 +74,7 @@ struct platform_device_info {
u64 dma_mask;

struct property_entry *properties;
+ void (*pre_add_cb)(struct device *);
extern struct platform_device *platform_device_register_full(
const struct platform_device_info *pdevinfo);

Plug pre_add_cb with your ACPI callback where you can do all the
processing you want before the device is actually added.

Great, will do, thank you very much!