Re: [PATCH 6/9] drm/msm/dsi_phy_28nm_8960: Use stack memory for temporary clock names

From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
To: Marijn Suijten <marijn.suijten@somainline.org>
Cc: phone-devel@vger.kernel.org, Stephen Boyd <sboyd@kernel.org>,
	~postmarketos/upstreaming@lists.sr.ht,
	AngeloGioacchino Del Regno 
	<angelogioacchino.delregno@somainline.org>,
	Konrad Dybcio <konrad.dybcio@somainline.org>,
	Martin Botka <martin.botka@somainline.org>,
	Jami Kettunen <jami.kettunen@somainline.org>,
	Michael Turquette <mturquette@baylibre.com>,
	Rob Clark <robdclark@gmail.com>,
	Abhinav Kumar <quic_abhinavk@quicinc.com>,
	Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
	Daniel Vetter <daniel@ffwll.ch>,
	Rajeev Nandan <quic_rajeevny@quicinc.com>,
	Vladimir Lypak <vladimir.lypak@gmail.com>,
	Arnd Bergmann <arnd@arndb.de>, Jonathan Marek <jonathan@marek.ca>,
	linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
	freedreno@lists.freedesktop.org
Subject: Re: [PATCH 6/9] drm/msm/dsi_phy_28nm_8960: Use stack memory for temporary clock names
Date: Tue, 24 May 2022 01:45:29 +0300	[thread overview]
Message-ID: <CAA8EJpqhqtc1A0SJqAhOveZcdsBEjPNZLpR3tTM2L3+p3QtiWA@mail.gmail.com> (raw)
In-Reply-To: <20220523213837.1016542-7-marijn.suijten@somainline.org>

On Tue, 24 May 2022 at 00:38, Marijn Suijten
<marijn.suijten@somainline.org> wrote:
>
> The clock names formatted into the hw_clk's init structure are only used
> for the duration of the registration function where they are kstrdup'ed,
> making it unnecessary to keep the allocations alive for the duration of
> the device (through devm).
>
> Just like the other DSI PHY PLL clock trees, use a stack-local char
> array and save on memory outside of the pll_28nm_register function.
>
> Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Nit: we can use clk_name instead of vco_name too.

> ---
>  drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c | 10 +---------
>  1 file changed, 1 insertion(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c
> index 943a7e847c90..554978fc434d 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c
> @@ -383,7 +383,7 @@ static int dsi_28nm_pll_restore_state(struct msm_dsi_phy *phy)
>
>  static int pll_28nm_register(struct dsi_pll_28nm *pll_28nm, struct clk_hw **provided_clocks)
>  {
> -       char *clk_name, *vco_name;
> +       char clk_name[32], vco_name[32];
>         struct clk_init_data vco_init = {
>                 .parent_data = &(const struct clk_parent_data) {
>                         .fw_name = "ref",
> @@ -404,14 +404,6 @@ static int pll_28nm_register(struct dsi_pll_28nm *pll_28nm, struct clk_hw **prov
>         if (!bytediv)
>                 return -ENOMEM;
>
> -       vco_name = devm_kzalloc(dev, 32, GFP_KERNEL);
> -       if (!vco_name)
> -               return -ENOMEM;
> -
> -       clk_name = devm_kzalloc(dev, 32, GFP_KERNEL);
> -       if (!clk_name)
> -               return -ENOMEM;
> -
>         snprintf(vco_name, 32, "dsi%dvco_clk", pll_28nm->phy->id);
>         vco_init.name = vco_name;
>
> --
> 2.36.1
>

-- 
With best wishes
Dmitry