-----Original Message-----
From: Hans de Goede [mailto:hdegoede at redhat.com]
Sent: Wednesday, August 29, 2018 11:22 PM

[...]

On 29-08-18 16:41, Dong Aisheng wrote:

quoted

Switching to use clk_bulk API to simplify clock operations.

Cc: Hans de Goede <redacted>
Cc: Bartlomiej Zolnierkiewicz <redacted>
Cc: linux-fbdev at vger.kernel.org
Cc: Masahiro Yamada <redacted>
Cc: Stephen Boyd <redacted>
Tested-by: Thor Thayer <redacted>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
v4->v5:
  * fix wrong setting of par->clks_enabled
v3->v4:
  * no changes
v2->v3:
  * fix a build warning on x86 platform due to a wrong
    of the prototype of simplefb_clocks_enable
v1->v2:
  * switch to clk_bulk_get_all from of_clk_bulk_get_all
---
  drivers/video/fbdev/simplefb.c | 68 +++++++++---------------------------------
  1 file changed, 14 insertions(+), 54 deletions(-)

diff --git a/drivers/video/fbdev/simplefb.c

b/drivers/video/fbdev/simplefb.c index 9a9d748..8d1fbd6 100644

--- a/drivers/video/fbdev/simplefb.c
+++ b/drivers/video/fbdev/simplefb.c

@@ -182,7 +182,7 @@ struct simplefb_par {
  #if defined CONFIG_OF && defined CONFIG_COMMON_CLK
  	bool clks_enabled;
  	unsigned int clk_count;
-	struct clk **clks;
+	struct clk_bulk_data *clks;
  #endif
  #if defined CONFIG_OF && defined CONFIG_REGULATOR
  	bool regulators_enabled;

@@ -214,37 +214,13 @@ static int simplefb_clocks_get(struct simplefb_par

*par,

quoted

  			       struct platform_device *pdev)
  {
  	struct device_node *np = pdev->dev.of_node;
-	struct clk *clock;
-	int i;

  	if (dev_get_platdata(&pdev->dev) || !np)
  		return 0;

-	par->clk_count = of_clk_get_parent_count(np);
-	if (!par->clk_count)
-		return 0;
-
-	par->clks = kcalloc(par->clk_count, sizeof(struct clk *), GFP_KERNEL);
-	if (!par->clks)
-		return -ENOMEM;
-
-	for (i = 0; i < par->clk_count; i++) {
-		clock = of_clk_get(np, i);
-		if (IS_ERR(clock)) {
-			if (PTR_ERR(clock) == -EPROBE_DEFER) {
-				while (--i >= 0) {
-					if (par->clks[i])
-						clk_put(par->clks[i]);
-				}
-				kfree(par->clks);
-				return -EPROBE_DEFER;
-			}
-			dev_err(&pdev->dev, "%s: clock %d not found: %ld\n",
-				__func__, i, PTR_ERR(clock));
-			continue;
-		}
-		par->clks[i] = clock;
-	}
+	par->clk_count = clk_bulk_get_all(&pdev->dev, &par->clks);
+	if ((par->clk_count < 0) && (par->clk_count == -EPROBE_DEFER))
+		return -EPROBE_DEFER;

I just noticed this now, but clk_count is unsigned so it will never be < 0, please
make it signed.

Good findings.

Also there is no need to check for < 0 just (par->clk_count == -EPROBE_DEFER)
is enough (if that is true < 0 also always is true).

Yes, you're right.

quoted

  	return 0;
  }

@@ -252,39 +228,23 @@ static int simplefb_clocks_get(struct simplefb_par

*par,

quoted

  static void simplefb_clocks_enable(struct simplefb_par *par,
  				   struct platform_device *pdev)
  {
-	int i, ret;
+	int ret;

-	for (i = 0; i < par->clk_count; i++) {
-		if (par->clks[i]) {
-			ret = clk_prepare_enable(par->clks[i]);
-			if (ret) {
-				dev_err(&pdev->dev,
-					"%s: failed to enable clock %d: %d\n",
-					__func__, i, ret);
-				clk_put(par->clks[i]);
-				par->clks[i] = NULL;
-			}
-		}
+	ret = clk_bulk_prepare_enable(par->clk_count, par->clks);

Hmm, what happens if par->clk_count < 0 (another <0 value then
-EPROBEDEFER) ?

Good catch. I will add a checking of it.

diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c
index 477e008..89fb1e7 100644
--- a/drivers/video/fbdev/simplefb.c
+++ b/drivers/video/fbdev/simplefb.c

@@ -230,6 +230,9 @@ static void simplefb_clocks_enable(struct simplefb_par *par,
 {
        int ret;
 
+       if (par->clk_count <= 0)
+               return;
+
        ret = clk_bulk_prepare_enable(par->clk_count, par->clks);
        if (ret)
                dev_warn(&pdev->dev, "failed to enable clocks\n");

@@ -239,6 +242,9 @@ static void simplefb_clocks_enable(struct simplefb_par *par,
 
 static void simplefb_clocks_destroy(struct simplefb_par *par)
 {
+       if (par->clk_count <= 0)
+               return;
+
        if (par->clks_enabled)
                clk_bulk_disable_unprepare(par->clk_count, par->clks);

quoted

+	if (ret) {
+		par->clks_enabled = false;

No need to set false here.

Got it. Then let's reply on the kzalloc

quoted

+		dev_warn(&pdev->dev, "failed to enable clocks\n");
+	} else {
+		par->clks_enabled = true;
  	}
-	par->clks_enabled = true;
  }

  static void simplefb_clocks_destroy(struct simplefb_par *par)
  {
-	int i;
-
-	if (!par->clks)
-		return;
-
-	for (i = 0; i < par->clk_count; i++) {
-		if (par->clks[i]) {
-			if (par->clks_enabled)
-				clk_disable_unprepare(par->clks[i]);
-			clk_put(par->clks[i]);
-		}
-	}
+	if (par->clks_enabled)
+		clk_bulk_disable_unprepare(par->clk_count, par->clks);

-	kfree(par->clks);
+	clk_bulk_put_all(par->clk_count, par->clks);

Again what about par->clk_count < 0 ?

Regards,

Hans

Will resend a new patch series. Thanks for the carefully review.

Regards
Dong Aisheng