Re: [PATCH v2 01/11] clk: imx: Add correct failure handling for clk based helpers

From: Leonard Crestez <leonard.crestez@nxp.com>
To: Abel Vesa <abel.vesa@nxp.com>, Shawn Guo <shawnguo@kernel.org>,
	Stephen Boyd <sboyd@kernel.org>
Cc: Aisheng Dong <aisheng.dong@nxp.com>,
	Sascha Hauer <kernel@pengutronix.de>,
	Jacky Bai <ping.bai@nxp.com>, Peng Fan <peng.fan@nxp.com>,
	dl-linux-imx <linux-imx@nxp.com>,
	"linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 01/11] clk: imx: Add correct failure handling for clk based helpers
Date: Fri, 22 Nov 2019 21:48:25 +0000	[thread overview]
Message-ID: <VI1PR04MB70231491C8375159CB07702BEE490@VI1PR04MB7023.eurprd04.prod.outlook.com> (raw)
In-Reply-To: 1574419679-3813-2-git-send-email-abel.vesa@nxp.com

On 2019-11-22 12:48 PM, Abel Vesa wrote:
> If the clk_hw based API returns an error, trying to return the clk from
> hw will end up in a NULL pointer dereference. So adding the to_clk
> checker and using it inside every clk based macro helper we handle that
> case correctly.
> 
> This to_clk is also temporary and will go away along with the clk based
> macro helpers once there is no user that need them anymore.
> 
> Signed-off-by: Abel Vesa <abel.vesa@nxp.com>

Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>

> ---
>   drivers/clk/imx/clk.h | 37 ++++++++++++++++++++++---------------
>   1 file changed, 22 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
> index bc5bb6a..30ddbc1 100644
> --- a/drivers/clk/imx/clk.h
> +++ b/drivers/clk/imx/clk.h
> @@ -54,48 +54,48 @@ extern struct imx_pll14xx_clk imx_1416x_pll;
>   extern struct imx_pll14xx_clk imx_1443x_pll;
>   
>   #define imx_clk_cpu(name, parent_name, div, mux, pll, step) \
> -	imx_clk_hw_cpu(name, parent_name, div, mux, pll, step)->clk
> +	to_clk(imx_clk_hw_cpu(name, parent_name, div, mux, pll, step))
>   
>   #define clk_register_gate2(dev, name, parent_name, flags, reg, bit_idx, \
>   				cgr_val, clk_gate_flags, lock, share_count) \
> -	clk_hw_register_gate2(dev, name, parent_name, flags, reg, bit_idx, \
> -				cgr_val, clk_gate_flags, lock, share_count)->clk
> +	to_clk(clk_hw_register_gate2(dev, name, parent_name, flags, reg, bit_idx, \
> +				cgr_val, clk_gate_flags, lock, share_count))
>   
>   #define imx_clk_pllv3(type, name, parent_name, base, div_mask) \
> -	imx_clk_hw_pllv3(type, name, parent_name, base, div_mask)->clk
> +	to_clk(imx_clk_hw_pllv3(type, name, parent_name, base, div_mask))
>   
>   #define imx_clk_pfd(name, parent_name, reg, idx) \
> -	imx_clk_hw_pfd(name, parent_name, reg, idx)->clk
> +	to_clk(imx_clk_hw_pfd(name, parent_name, reg, idx))
>   
>   #define imx_clk_gate_exclusive(name, parent, reg, shift, exclusive_mask) \
> -	imx_clk_hw_gate_exclusive(name, parent, reg, shift, exclusive_mask)->clk
> +	to_clk(imx_clk_hw_gate_exclusive(name, parent, reg, shift, exclusive_mask))
>   
>   #define imx_clk_fixed_factor(name, parent, mult, div) \
> -	imx_clk_hw_fixed_factor(name, parent, mult, div)->clk
> +	to_clk(imx_clk_hw_fixed_factor(name, parent, mult, div))
>   
>   #define imx_clk_divider2(name, parent, reg, shift, width) \
> -	imx_clk_hw_divider2(name, parent, reg, shift, width)->clk
> +	to_clk(imx_clk_hw_divider2(name, parent, reg, shift, width))
>   
>   #define imx_clk_gate_dis(name, parent, reg, shift) \
> -	imx_clk_hw_gate_dis(name, parent, reg, shift)->clk
> +	to_clk(imx_clk_hw_gate_dis(name, parent, reg, shift))
>   
>   #define imx_clk_gate2(name, parent, reg, shift) \
> -	imx_clk_hw_gate2(name, parent, reg, shift)->clk
> +	to_clk(imx_clk_hw_gate2(name, parent, reg, shift))
>   
>   #define imx_clk_gate2_flags(name, parent, reg, shift, flags) \
> -	imx_clk_hw_gate2_flags(name, parent, reg, shift, flags)->clk
> +	to_clk(imx_clk_hw_gate2_flags(name, parent, reg, shift, flags))
>   
>   #define imx_clk_gate2_shared2(name, parent, reg, shift, share_count) \
> -	imx_clk_hw_gate2_shared2(name, parent, reg, shift, share_count)->clk
> +	to_clk(imx_clk_hw_gate2_shared2(name, parent, reg, shift, share_count))
>   
>   #define imx_clk_gate3(name, parent, reg, shift) \
> -	imx_clk_hw_gate3(name, parent, reg, shift)->clk
> +	to_clk(imx_clk_hw_gate3(name, parent, reg, shift))
>   
>   #define imx_clk_gate4(name, parent, reg, shift) \
> -	imx_clk_hw_gate4(name, parent, reg, shift)->clk
> +	to_clk(imx_clk_hw_gate4(name, parent, reg, shift))
>   
>   #define imx_clk_mux(name, reg, shift, width, parents, num_parents) \
> -	imx_clk_hw_mux(name, reg, shift, width, parents, num_parents)->clk
> +	to_clk(imx_clk_hw_mux(name, reg, shift, width, parents, num_parents))
>   
>   struct clk *imx_clk_pll14xx(const char *name, const char *parent_name,
>   		 void __iomem *base, const struct imx_pll14xx_clk *pll_clk);
> @@ -198,6 +198,13 @@ struct clk_hw *imx_clk_hw_fixup_mux(const char *name, void __iomem *reg,
>   			      u8 shift, u8 width, const char * const *parents,
>   			      int num_parents, void (*fixup)(u32 *val));
>   
> +static inline struct clk *to_clk(struct clk_hw *hw)
> +{
> +	if (IS_ERR_OR_NULL(hw))
> +		return ERR_CAST(hw);
> +	return hw->clk;
> +}
> +
>   static inline struct clk *imx_clk_fixed(const char *name, int rate)
>   {
>   	return clk_register_fixed_rate(NULL, name, NULL, 0, rate);
>