Re: [PATCH next] i2c: qcom-cci: Fix error checking in cci_probe()

[Bryan O'Donoghue <bryan.odonoghue@linaro.org>]

On 23/08/2023 20:42, Harshit Mogalapalli wrote:
> devm_clk_bulk_get_all() can return zero when no clocks are obtained.
> Passing zero to dev_err_probe() is a success which is incorrect.
> 
> Fixes: 605efbf43813 ("i2c: qcom-cci: Use dev_err_probe in probe function")
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
> ---
> Only compile tested, found by static analysis with smatch.
> 
> https://lore.kernel.org/all/CAA8EJprTOjbOy7N5+8NiJaNNhK+_btdUUFcpHKPkMuCZj5umMA@mail.gmail.com/
> ^^ I reported initially here, Dmitry suggested we need to fix it in a
> different patch.
> 
> the Fixes commit used above pointed this bug, but the real fixes tag is this:
> Fixes: e517526195de ("i2c: Add Qualcomm CCI I2C driver")
> ---
>   drivers/i2c/busses/i2c-qcom-cci.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
> index cf13abec05f1..414882c57d7f 100644
> --- a/drivers/i2c/busses/i2c-qcom-cci.c
> +++ b/drivers/i2c/busses/i2c-qcom-cci.c
> @@ -588,8 +588,10 @@ static int cci_probe(struct platform_device *pdev)
>   	/* Clocks */
>   
>   	ret = devm_clk_bulk_get_all(dev, &cci->clocks);
> -	if (ret < 1)
> +	if (ret < 0)
>   		return dev_err_probe(dev, ret, "failed to get clocks\n");
> +	else if (!ret)
> +		return dev_err_probe(dev, -EINVAL, "not enough clocks in DT\n");
>   	cci->nclocks = ret;
>   
>   	/* Retrieve CCI clock rate */
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>