On Wed, Jul 1, 2015 at 10:21 PM, Daniel Kurtz <djkurtz@xxxxxxxxxxxx> wrote:
> Hi James,
>
> To be precise, it is the CLK_TOP clocks that have CLK_APMIXED PLLs as
> their parents, so we cannot enable the CLK_TOP critical clocks until
> the CLK_APMIXED clocks have all been registered.
>
> Please add something like the above to the commit message.
>
> More comments inline...
>
> On Tue, Jun 30, 2015 at 10:58 AM, James Liao <jamesjj.liao@xxxxxxxxxxxx> wrote:
>> From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
>>
>> On the MT8173 the clocks are provided by different units. To enable
>> the critical clocks we must be sure that all parent clocks are already
>> registered, otherwise the parents of the critical clocks end up being
>> unused and get disabled later. To find a place where all parents are
>> registered we try each time after we've registered some clocks if
>> all known providers are present now and only then we enable the critical
>> clocks
>>
>> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
>> Signed-off-by: James Liao <jamesjj.liao@xxxxxxxxxxxx>
>> ---
>> drivers/clk/mediatek/clk-mt8173.c | 26 +++++++++++++++++++++-----
>> 1 file changed, 21 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/clk/mediatek/clk-mt8173.c b/drivers/clk/mediatek/clk-mt8173.c
>> index 4b9e04c..c483336 100644
>> --- a/drivers/clk/mediatek/clk-mt8173.c
>> +++ b/drivers/clk/mediatek/clk-mt8173.c
>> @@ -700,6 +700,22 @@ static const struct mtk_composite peri_clks[] __initconst = {
>> MUX(CLK_PERI_UART3_SEL, "uart3_ck_sel", uart_ck_sel_parents, 0x40c, 3, 1),
>> };
>>
>> +static struct clk_onecell_data *mt8173_top_clk_data;
>> +static struct clk_onecell_data *mt8173_pll_clk_data;
>
> These globals can be:
> __initdata
Oops, never mind about this comment...
Using "__initdata" for uninitialized variables doesn't make sense -
"__initdata" is for initialization data, not variables themselves.
Sorry for the noise,
-Dan
>
>> +
>> +static void mtk_clk_enable_critical(void)
>
> And this function is:
>
> static void __init
>
> Other than the above, this one is:
>
> Reviewed-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
>
> -Dan
>
>> +{
>> + if (!mt8173_top_clk_data || !mt8173_pll_clk_data)
>> + return;
>> +
>> + clk_prepare_enable(mt8173_pll_clk_data->clks[CLK_APMIXED_ARMCA15PLL]);
>> + clk_prepare_enable(mt8173_pll_clk_data->clks[CLK_APMIXED_ARMCA7PLL]);
>> + clk_prepare_enable(mt8173_top_clk_data->clks[CLK_TOP_MEM_SEL]);
>> + clk_prepare_enable(mt8173_top_clk_data->clks[CLK_TOP_DDRPHYCFG_SEL]);
>> + clk_prepare_enable(mt8173_top_clk_data->clks[CLK_TOP_CCI400_SEL]);
>> + clk_prepare_enable(mt8173_top_clk_data->clks[CLK_TOP_RTC_SEL]);
>> +}
>> +
>> static void __init mtk_topckgen_init(struct device_node *node)
>> {
>> struct clk_onecell_data *clk_data;
>> @@ -712,19 +728,19 @@ static void __init mtk_topckgen_init(struct device_node *node)
>> return;
>> }
>>
>> - clk_data = mtk_alloc_clk_data(CLK_TOP_NR_CLK);
>> + mt8173_top_clk_data = clk_data = mtk_alloc_clk_data(CLK_TOP_NR_CLK);
>>
>> mtk_clk_register_factors(root_clk_alias, ARRAY_SIZE(root_clk_alias), clk_data);
>> mtk_clk_register_factors(top_divs, ARRAY_SIZE(top_divs), clk_data);
>> mtk_clk_register_composites(top_muxes, ARRAY_SIZE(top_muxes), base,
>> &mt8173_clk_lock, clk_data);
>>
>> - clk_prepare_enable(clk_data->clks[CLK_TOP_CCI400_SEL]);
>> -
>> r = of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
>> if (r)
>> pr_err("%s(): could not register clock provider: %d\n",
>> __func__, r);
>> +
>> + mtk_clk_enable_critical();
>> }
>> CLK_OF_DECLARE(mtk_topckgen, "mediatek,mt8173-topckgen", mtk_topckgen_init);
>>
>> @@ -818,13 +834,13 @@ static void __init mtk_apmixedsys_init(struct device_node *node)
>> {
>> struct clk_onecell_data *clk_data;
>>
>> - clk_data = mtk_alloc_clk_data(CLK_APMIXED_NR_CLK);
>> + mt8173_pll_clk_data = clk_data = mtk_alloc_clk_data(CLK_APMIXED_NR_CLK);
>> if (!clk_data)
>> return;
>>
>> mtk_clk_register_plls(node, plls, ARRAY_SIZE(plls), clk_data);
>>
>> - clk_prepare_enable(clk_data->clks[CLK_APMIXED_ARMCA15PLL]);
>> + mtk_clk_enable_critical();
>> }
>> CLK_OF_DECLARE(mtk_apmixedsys, "mediatek,mt8173-apmixedsys",
>> mtk_apmixedsys_init);
>> --
>> 1.8.1.1.dirty
>>
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