Hi Sjoerd
We double check this problem, yes, board will hang if aclk is disabled
when setting vop register.
Acked-by: Mark Yao <mark.yao at rock-chips.com>
Thanks for this fix.
On 2015?09?29? 17:28, Sjoerd Simons wrote:
> When doing the initial setup both the hclk and the aclk need to be
> enabled otherwise the board will simply hang. This only occurs when
> building the vop driver as a module, when its built-in the initial setup
> happens to run before the clock framework shuts of unused clocks
> (including the aclk).
>
> While there also switch to doing prepare and enable in one step rather
> then separate steps to reduce the amount of code required.
>
> Signed-off-by: Sjoerd Simons <sjoerd.simons at collabora.co.uk>
>
> ---
>
> drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 36 +++++++++++------------------
> 1 file changed, 14 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index 5d8ae5e..48719df 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -1575,32 +1575,25 @@ static int vop_initial(struct vop *vop)
> return PTR_ERR(vop->dclk);
> }
>
> - ret = clk_prepare(vop->hclk);
> - if (ret < 0) {
> - dev_err(vop->dev, "failed to prepare hclk\n");
> - return ret;
> - }
> -
> ret = clk_prepare(vop->dclk);
> if (ret < 0) {
> dev_err(vop->dev, "failed to prepare dclk\n");
> - goto err_unprepare_hclk;
> + return ret;
> }
>
> - ret = clk_prepare(vop->aclk);
> + /* Enable both the hclk and aclk to setup the vop */
> + ret = clk_prepare_enable(vop->hclk);
> if (ret < 0) {
> - dev_err(vop->dev, "failed to prepare aclk\n");
> + dev_err(vop->dev, "failed to prepare/enable hclk\n");
> goto err_unprepare_dclk;
> }
>
> - /*
> - * enable hclk, so that we can config vop register.
> - */
> - ret = clk_enable(vop->hclk);
> + ret = clk_prepare_enable(vop->aclk);
> if (ret < 0) {
> - dev_err(vop->dev, "failed to prepare aclk\n");
> - goto err_unprepare_aclk;
> + dev_err(vop->dev, "failed to prepare/enable aclk\n");
> + goto err_disable_hclk;
> }
> +
> /*
> * do hclk_reset, reset all vop registers.
> */
> @@ -1608,7 +1601,7 @@ static int vop_initial(struct vop *vop)
> if (IS_ERR(ahb_rst)) {
> dev_err(vop->dev, "failed to get ahb reset\n");
> ret = PTR_ERR(ahb_rst);
> - goto err_disable_hclk;
> + goto err_disable_aclk;
> }
> reset_control_assert(ahb_rst);
> usleep_range(10, 20);
> @@ -1634,26 +1627,25 @@ static int vop_initial(struct vop *vop)
> if (IS_ERR(vop->dclk_rst)) {
> dev_err(vop->dev, "failed to get dclk reset\n");
> ret = PTR_ERR(vop->dclk_rst);
> - goto err_unprepare_aclk;
> + goto err_disable_aclk;
> }
> reset_control_assert(vop->dclk_rst);
> usleep_range(10, 20);
> reset_control_deassert(vop->dclk_rst);
>
> clk_disable(vop->hclk);
> + clk_disable(vop->aclk);
>
> vop->is_enabled = false;
>
> return 0;
>
> +err_disable_aclk:
> + clk_disable_unprepare(vop->aclk);
> err_disable_hclk:
> - clk_disable(vop->hclk);
> -err_unprepare_aclk:
> - clk_unprepare(vop->aclk);
> + clk_disable_unprepare(vop->hclk);
> err_unprepare_dclk:
> clk_unprepare(vop->dclk);
> -err_unprepare_hclk:
> - clk_unprepare(vop->hclk);
> return ret;
> }
>
--
?ark Yao
