linux-kernel - Re: [PATCH] clk: qcom: dispcc-sm8750: Drop incorrect CLK_SET_RATE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <802dff81-6fe3-41d4-a470-ad35a09ce191@linaro.org>
Date: Wed, 29 Jan 2025 16:55:29 +0100
From: neil.armstrong@...aro.org
To: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
 Bjorn Andersson <andersson@...nel.org>,
 Michael Turquette <mturquette@...libre.com>, Stephen Boyd
 <sboyd@...nel.org>, linux-arm-msm@...r.kernel.org,
 linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] clk: qcom: dispcc-sm8750: Drop incorrect
 CLK_SET_RATE_PARENT on byte intf parent

On 29/01/2025 16:45, Krzysztof Kozlowski wrote:
> The parent of disp_cc_mdss_byte0_intf_clk clock should not propagate up
> the rates, because this messes up entire clock hierarchy when setting
> clock rates in MSM DSI driver.
> 
> The dsi_link_clk_set_rate_6g() first sets entire clock hierarchy rates
> via dev_pm_opp_set_rate() on byte clock and then sets individual clock
> rates, like pixel and byte_intf clocks, to proper frequencies.  Having
> CLK_SET_RATE_PARENT caused that entire tree was re-calced and the byte
> clock received halved frequency.  Drop CLK_SET_RATE_PARENT to fix this
> and align with SM8550 and SM8650.
> 
> Fixes: f1080d8dab0f ("clk: qcom: dispcc-sm8750: Add SM8750 Display clock controller")
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
> 
> ---
> 
> Fix for v6.14-rcX.
> ---
>   drivers/clk/qcom/dispcc-sm8750.c | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/clk/qcom/dispcc-sm8750.c b/drivers/clk/qcom/dispcc-sm8750.c
> index 0358dff91da5..e9bca179998b 100644
> --- a/drivers/clk/qcom/dispcc-sm8750.c
> +++ b/drivers/clk/qcom/dispcc-sm8750.c
> @@ -827,7 +827,6 @@ static struct clk_regmap_div disp_cc_mdss_byte0_div_clk_src = {
>   			&disp_cc_mdss_byte0_clk_src.clkr.hw,
>   		},
>   		.num_parents = 1,
> -		.flags = CLK_SET_RATE_PARENT,
>   		.ops = &clk_regmap_div_ops,
>   	},
>   };
> @@ -842,7 +841,6 @@ static struct clk_regmap_div disp_cc_mdss_byte1_div_clk_src = {
>   			&disp_cc_mdss_byte1_clk_src.clkr.hw,
>   		},
>   		.num_parents = 1,
> -		.flags = CLK_SET_RATE_PARENT,
>   		.ops = &clk_regmap_div_ops,
>   	},
>   };

Reviewed-by: Neil Armstrong <neil.armstrong@...aro.org>