On 06/01/2016 11:19 PM, Thierry Reding wrote:
> On Wed, Jun 01, 2016 at 05:19:12PM +0800, Yakir Yang wrote:
>> There is a bug in RK3399 VOP, when bootloader/kernel only enable
>> VOP Big or VOP Little to display, then VOP IOMMU would failed to
>> reset at the initial time and VOP register couldn't write rightly.
>>
>> After do the pure reset of VOP module, then things back to right.
>>
>> Signed-off-by: Yakir Yang <ykk at rock-chips.com>
>> ---
>> drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 15 ++++++++++++++-
>> 1 file changed, 14 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> index 1c4d5b5..4150323 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
>> @@ -1292,7 +1292,7 @@ static int vop_initial(struct vop *vop)
>> {
>> const struct vop_data *vop_data = vop->data;
>> const struct vop_reg_data *init_table = vop_data->init_table;
>> - struct reset_control *ahb_rst;
>> + struct reset_control *ahb_rst, *axi_rst;
>> int i, ret;
>>
>> vop->hclk = devm_clk_get(vop->dev, "hclk_vop");
>> @@ -1331,6 +1331,19 @@ static int vop_initial(struct vop *vop)
>> }
>>
>> /*
>> + * do aclk_reset, reset all vop registers.
>> + */
>> + axi_rst = devm_reset_control_get(vop->dev, "axi");
> I don't think you want the managed version here since you only store
> this in a local variable and hence aren't going to need it afterwards.
> Just use reset_control_get() and ...
Great, but seems Mark would not accept this fix now :(
Maybe I should found the root cause why my bootloader/kernel would
broken the VOP.
Thanks,
- Yakir
>> + if (IS_ERR(axi_rst)) {
>> + dev_err(vop->dev, "failed to get axi reset\n");
>> + ret = PTR_ERR(axi_rst);
>> + goto err_disable_aclk;
>> + }
>> + reset_control_assert(axi_rst);
>> + usleep_range(10, 20);
>> + reset_control_deassert(axi_rst);
> call reset_control_put() here.
>
>> +
>> + /*
>> * do hclk_reset, reset all vop registers.
>> */
>> ahb_rst = devm_reset_control_get(vop->dev, "ahb");
> This uses the same pattern, so you might want to consider reworking this
> as well, though it should be a separate patch.
>
> Thierry
