Re: [PATCH 1/2] drm/meson: dw-hdmi: Disable clocks on driver teardown

Neil Armstrong
2020-11-20T12:27:12Z

On 20/11/2020 10:42, Marc Zyngier wrote:
> The HDMI driver request clocks early, but never disable them, leaving
> the clocks on even when the driver is removed.
>
> Fix it by slightly refactoring the clock code, and register a devm
> action that will eventually disable/unprepare the enabled clocks.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> drivers/gpu/drm/meson/meson_dw_hdmi.c | 43 ++++++++++++++++++---------
> 1 file changed, 29 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index 7f8eea494147..29623b309cb1 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -145,8 +145,6 @@ struct meson_dw_hdmi {
> struct reset_control *hdmitx_apb;
> struct reset_control *hdmitx_ctrl;
> struct reset_control *hdmitx_phy;
> - struct clk *hdmi_pclk;
> - struct clk *venci_clk;
> struct regulator *hdmi_supply;
> u32 irq_stat;
> struct dw_hdmi *hdmi;
> @@ -946,6 +944,29 @@ static void meson_disable_regulator(void *data)
> regulator_disable(data);
> }
>
> +static void meson_disable_clk(void *data)
> +{
> + clk_disable_unprepare(data);
> +}
> +
> +static int meson_enable_clk(struct device *dev, char *name)
> +{
> + struct clk *clk;
> + int ret;
> +
> + clk = devm_clk_get(dev, name);
> + if (IS_ERR(clk)) {
> + dev_err(dev, "Unable to get %s pclk\n", name);
> + return PTR_ERR(clk);
> + }
> +
> + ret = clk_prepare_enable(clk);
> + if (!ret)
> + ret = devm_add_action_or_reset(dev, meson_disable_clk, clk);
> +
> + return ret;
> +}
> +
> static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
> void *data)
> {
> @@ -1026,19 +1047,13 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
> if (IS_ERR(meson_dw_hdmi->hdmitx))
> return PTR_ERR(meson_dw_hdmi->hdmitx);
>
> - meson_dw_hdmi->hdmi_pclk = devm_clk_get(dev, "isfr");
> - if (IS_ERR(meson_dw_hdmi->hdmi_pclk)) {
> - dev_err(dev, "Unable to get HDMI pclk\n");
> - return PTR_ERR(meson_dw_hdmi->hdmi_pclk);
> - }
> - clk_prepare_enable(meson_dw_hdmi->hdmi_pclk);
> + ret = meson_enable_clk(dev, "isfr");
> + if (ret)
> + return ret;
>
> - meson_dw_hdmi->venci_clk = devm_clk_get(dev, "venci");
> - if (IS_ERR(meson_dw_hdmi->venci_clk)) {
> - dev_err(dev, "Unable to get venci clk\n");
> - return PTR_ERR(meson_dw_hdmi->venci_clk);
> - }
> - clk_prepare_enable(meson_dw_hdmi->venci_clk);
> + ret = meson_enable_clk(dev, "venci");
> + if (ret)
> + return ret;
>
> dw_plat_data->regm = devm_regmap_init(dev, NULL, meson_dw_hdmi,
> &meson_dw_hdmi_regmap_config);
>

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>