[PATCH v2] misc: atmel-ssc: Handle return value of clk_prepare_enable and clk_prepare

On 05/06/2017 at 14:53:30 +0530, Arvind Yadav wrote:

Hi,

Yes, Patch v1 was wrong that's why i have push v2.
clk_prepare and clk_prepare_enable can fail. There

No this is not true, they will never fail for the SSC.

is not harm to check it's return value. It'll not impact present
functionality.

It does impact boot time, this patch adds 112 bytes to a compressed
kernel for no reason.

-arvind

On Sunday 04 June 2017 03:47 AM, Alexandre Belloni wrote:

quoted

Hi,

It is getting tiring to get patches that are nor even compile tested
resulting from whatever static analysis tool you used.

This patch has almost no value and v1 was clearly wrong.

Do you realize clk_prepare and clk_prepare_enable will never fail for
the SSC?

On 02/06/2017 at 11:09:02 +0530, Arvind Yadav wrote:

quoted

clk_prepare_enable() and clk_prepare() can fail here and
we must check its return value.

Signed-off-by: Arvind Yadav <redacted>
---
  drivers/misc/atmel-ssc.c | 12 ++++++++++--
  1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
index b2a0340..df34b81 100644
--- a/drivers/misc/atmel-ssc.c
+++ b/drivers/misc/atmel-ssc.c

@@ -30,6 +30,7 @@ struct ssc_device *ssc_request(unsigned int ssc_num)
  {
  	int ssc_valid = 0;
  	struct ssc_device *ssc;
+	int ret;
  	spin_lock(&user_lock);
  	list_for_each_entry(ssc, &ssc_list, list) {

@@ -60,7 +61,11 @@ struct ssc_device *ssc_request(unsigned int ssc_num)
  	ssc->user++;
  	spin_unlock(&user_lock);
-	clk_prepare(ssc->clk);
+	ret = clk_prepare(ssc->clk);
+	if (ret) {
+		pr_err("Failed to prepare clock\n");
+		return ERR_PTR(ret);
+	}
  	return ssc;
  }

@@ -195,6 +200,7 @@ static int ssc_probe(struct platform_device *pdev)
  	struct resource *regs;
  	struct ssc_device *ssc;
  	const struct atmel_ssc_platform_data *plat_dat;
+	int ret;
  	ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
  	if (!ssc) {

@@ -229,7 +235,9 @@ static int ssc_probe(struct platform_device *pdev)
  	}
  	/* disable all interrupts */
-	clk_prepare_enable(ssc->clk);
+	ret = clk_prepare_enable(ssc->clk);
+	if (ret)
+		return ret;
  	ssc_writel(ssc->regs, IDR, -1);
  	ssc_readl(ssc->regs, SR);
  	clk_disable_unprepare(ssc->clk);

-- 
1.9.1


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-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com