On 12.06.2023 12:17, Stephan Gerhold wrote:
> On Mon, Jun 12, 2023 at 11:22:48AM +0200, Konrad Dybcio wrote:
>> The config/periph/system NoC clocks are wholly controlled by the
>> RPM firmware and Linux should never ever alter their configuration.
>>
>> Switch them over to read-only ops to avoid that.
>>
>> Fixes: b1e010c0730a ("clk: qcom: Add MSM8996 Global Clock Control (GCC) driver")
>> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
>> ---
>> drivers/clk/qcom/gcc-msm8996.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/clk/qcom/gcc-msm8996.c b/drivers/clk/qcom/gcc-msm8996.c
>> index 5e44d1bcca9e..588e3b67657a 100644
>> --- a/drivers/clk/qcom/gcc-msm8996.c
>> +++ b/drivers/clk/qcom/gcc-msm8996.c
>> @@ -264,7 +264,7 @@ static struct clk_rcg2 system_noc_clk_src = {
>> .name = "system_noc_clk_src",
>> .parent_data = gcc_xo_gpll0_gpll0_early_div,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0_gpll0_early_div),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>> @@ -284,7 +284,7 @@ static struct clk_rcg2 config_noc_clk_src = {
>> .name = "config_noc_clk_src",
>> .parent_data = gcc_xo_gpll0,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>> @@ -306,7 +306,7 @@ static struct clk_rcg2 periph_noc_clk_src = {
>> .name = "periph_noc_clk_src",
>> .parent_data = gcc_xo_gpll0,
>> .num_parents = ARRAY_SIZE(gcc_xo_gpll0),
>> - .ops = &clk_rcg2_ops,
>> + .ops = &clk_rcg2_ro_ops,
>> },
>> };
>>
>
> If the rcg is read-only then it shouldn't need a .freq_tbl (the
> .recalc_rate() works without it). These clocks have one for some reason.
.get_parent needs it
>
> Maybe we should also set .flags = CLK_GET_RATE_NOCACHE to ensure that
> clk_get_rate() doesn't return some stale value? Although I'm not sure if
> it's enough to set it here or if it would need to be set on all child
> clocks as well.
Hm, I'm not sure if it makes sense for the children..
Konrad
>
> Thanks,
> Stephan
