Re: [PATCH v3 08/10] clk: clock-wizard: Make the output names unique

From: Dan Carpenter
Date: Thu Nov 28 2019 - 02:45:38 EST


On Thu, Nov 28, 2019 at 12:06:15PM +0530, shubhrajyoti.datta@xxxxxxxxx wrote:
> From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
>
> Incase there are more than one instance of the clocking wizard.
> And if the output name given is the same then the probe fails.
> Fix the same by appending the device name to the output name to
> make it unique.
>
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
> ---
> drivers/clk/clk-xlnx-clock-wizard.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/clk/clk-xlnx-clock-wizard.c b/drivers/clk/clk-xlnx-clock-wizard.c
> index 75ea745..9993543 100644
> --- a/drivers/clk/clk-xlnx-clock-wizard.c
> +++ b/drivers/clk/clk-xlnx-clock-wizard.c
> @@ -555,6 +555,9 @@ static int clk_wzrd_probe(struct platform_device *pdev)
> ret = -ENOMEM;
> goto err_disable_clk;
> }
> + outputs = of_property_count_strings(np, "clock-output-names");
> + if (outputs == 1)
> + flags = CLK_SET_RATE_PARENT;
> clk_wzrd->clks_internal[wzrd_clk_mul] = clk_register_fixed_factor
> (&pdev->dev, clk_name,
> __clk_get_name(clk_wzrd->clk_in1),
> @@ -566,9 +569,6 @@ static int clk_wzrd_probe(struct platform_device *pdev)
> goto err_disable_clk;
> }
>
> - outputs = of_property_count_strings(np, "clock-output-names");
> - if (outputs == 1)
> - flags = CLK_SET_RATE_PARENT;
> clk_name = kasprintf(GFP_KERNEL, "%s_mul_div", dev_name(&pdev->dev));
> if (!clk_name) {
> ret = -ENOMEM;
> @@ -591,6 +591,7 @@ static int clk_wzrd_probe(struct platform_device *pdev)
> /* register div per output */
> for (i = outputs - 1; i >= 0 ; i--) {
> const char *clkout_name;
> + const char *clkout_name_wiz;
>
> if (of_property_read_string_index(np, "clock-output-names", i,
> &clkout_name)) {
> @@ -599,9 +600,11 @@ static int clk_wzrd_probe(struct platform_device *pdev)
> ret = -EINVAL;
> goto err_rm_int_clks;
> }
> + clkout_name_wiz = kasprintf(GFP_KERNEL, "%s_%s",
> + dev_name(&pdev->dev), clkout_name);

If this kasprintf() crashes then clk_wzrd_register_divf() will fail.
But that was a headache to review. Just add a check for NULL. We need
a kfree() as well.

One alternative would be to just declare a buffer on the stack and use
snprintf(). We don't need to keep the name around after the call to
clk_wzrd_register_divf().

regards,
dan carpenter