Re: [PATCH 2/3] drm: mediatek: remove clk_unprepare() in mtk_drm_crtc_destroy()

[Hsin-Yi Wang]

On Wed, May 29, 2019 at 1:58 PM CK Hu <ck.hu@xxxxxxxxxxxx> wrote:
>
> Hi, Hsin-Yi:
>
> On Mon, 2019-05-27 at 12:50 +0800, Hsin-Yi Wang wrote:
> > There is no clk_prepare() called in mtk_drm_crtc_reset(), when unbinding
> > drm device, mtk_drm_crtc_destroy() will be triggered, and the clocks will
> > be disabled and unprepared in mtk_crtc_ddp_clk_disable. If clk_unprepare()
> > is called here, we'll get warnings[1], so remove clk_unprepare() here.
>
> In original code, clk_prepare() is called in mtk_drm_crtc_create() and
> clk_unprepare() is called in mtk_drm_crtc_destroy(). This looks correct.

clk_prepare() is removed in https://patchwork.kernel.org/patch/10872777/.

> I don't know why we should do any thing about clock in
> mtk_drm_crtc_reset(). To debug this, the first step is to print message
> when mediatek drm call clk_prepare() and clk_unprepare(). If these two
> interface is called in pair, I think we should not modify mediatek drm
> driver, the bug maybe in clock driver.
>