Re: [PATCH v5 07/14] ahci-platform: "Library-ise" ahci_probe functionality

On 01/27/2014 01:28 PM, Hans de Goede wrote:

Hi,

On 01/27/2014 12:03 PM, Roger Quadros wrote:

quoted

On 01/27/2014 12:51 PM, Hans de Goede wrote:

quoted

Hi,

On 01/27/2014 11:39 AM, Roger Quadros wrote:

quoted

Hi,

On 01/22/2014 09:04 PM, Hans de Goede wrote:

<snip>

quoted

quoted

--- a/include/linux/ahci_platform.h
+++ b/include/linux/ahci_platform.h

@@ -20,7 +20,13 @@
   struct device;
   struct ata_port_info;
   struct ahci_host_priv;
+struct platform_device;

+/*
+ * Note ahci_platform_data is deprecated. New drivers which need to override
+ * any of these, should instead declare there own platform_driver struct, and
+ * use ahci_platform* functions in their own probe, suspend and resume methods.
+ */
   struct ahci_platform_data {
       int (*init)(struct device *dev, struct ahci_host_priv *hpriv);
       void (*exit)(struct device *dev);

@@ -35,5 +41,13 @@ int ahci_platform_enable_clks(struct ahci_host_priv *hpriv);
   void ahci_platform_disable_clks(struct ahci_host_priv *hpriv);
   int ahci_platform_enable_resources(struct ahci_host_priv *hpriv);
   void ahci_platform_disable_resources(struct ahci_host_priv *hpriv);
+struct ahci_host_priv *ahci_platform_get_resources(
+    struct platform_device *pdev);

Why not use 'struct device' as the argument?

Because of calls to platform_get_resource inside the function.

quoted

quoted

+void ahci_platform_put_resources(struct ahci_host_priv *hpriv);

Can we have 'struct device' as the argument? Else it becomes
impossible to get 'struct device' from 'hpriv' if we need to call e.g.
pm_runtime_*() APIs.

The plan for is for this function to go away once we have a
devm version of of_clk_get, so if you need to put pm_runtime_calls
somewhere, please don't put them here. This sounds like something which
should go in enable / disable resources instead ?

OK. I need to add pm_runtime_enable() + pm_runtime_get_sync() during
initialization and pm_runtime_put_sync() + pm_runtime_disable() during cleanup.

Note that enable / disable resources will get called by (the default implementations
of) suspend / resume too.

If that is undesirable then I take back what I said before and
ahci_platform_put_resources' prototype should be changed to:

void ahci_platform_put_resources(struct device *dev, struct ahci_host_priv *hpriv);

And we will need to keep it around even after we get devm_of_clk_get.

quoted

If ahci_platform_enable/disable_resources is the right place then we must be
able to access struct device from there.

Right, and if not we need to access it from ahci_platform_put_resources(),
which is in essence the same problem.

quoted

Is it a good to add 'struct device *dev' into the 'struct ahci_host_priv'?
Then you can leave this series as is and i'll add a new patch for that.

Normally we get a device * as argument, and get to hpriv like this:

        struct ata_host *host = dev_get_drvdata(dev);
        struct ahci_host_priv *hpriv = host->private_data;

So having a dev * in hpriv is normally not useful.

But the ata_host gets allocated after the first ahci_platform_enable_resources
call, so we cannot use this there. Likewise disable_resources / put_resources
is used in error handling paths in probe where we don't have an ata_host yet,
so my vote goes to adding a "struct device *dev" as first argument, like I
suggested above for ahci_platform_put_resources.

This can be done as an add-on patch (if you do don't forget to also fix
ahci_sunxi.c and ahci_imx.c), or I can respin my series to have this from
day one.

If you want me to do a respin, please let me know which fix you'll need
(the put_resources or the enable/disable one).

For now I'm using get/put_resources to enable runtime PM and enable the device
like in the below patch.

I'll make the necessary changes to ahci_platform_put_resources();

cheers,
-roger

diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 5ec6fe6..965f4b4 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c

@@ -23,6 +23,7 @@
 #include <linux/platform_device.h>
 #include <linux/libata.h>
 #include <linux/ahci_platform.h>
+#include <linux/pm_runtime.h>
 #include "ahci.h"
 
 static void ahci_host_stop(struct ata_host *host);

@@ -233,6 +234,9 @@ struct ahci_host_priv *ahci_platform_get_resources(
                }
        }
 
+       pm_runtime_enable(dev);
+       pm_runtime_get_sync(dev);
+
        return hpriv;
 
 free_clk:

@@ -246,6 +250,9 @@ void ahci_platform_put_resources(struct ahci_host_priv *hpriv)
 {
        int c;
 
+       pm_runtime_put_sync(dev);
+       pm_runtime_disable(dev);
+
        for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)
                clk_put(hpriv->clks[c]);
 }

@@ -478,6 +485,11 @@ int ahci_platform_resume(struct device *dev)
        if (rc)
                goto disable_resources;
 
+       /* We resumed so update PM runtime state */
+       pm_runtime_disable(dev);
+       pm_runtime_set_active(dev);
+       pm_runtime_enable(dev);
+
        return 0;
 
 disable_resources: