Re: [PATCH v6 09/10] clk: stm32: Fix ltdc's clock turn off by clk_disable_unused() after system enter shell

["gabriel.fernandez@xxxxxxxxxxx" <gabriel.fernandez@xxxxxxxxxxx>]

Hi Dillon,

You can add my Acked-by: Gabriel Fernandez <gabriel.fernandez@xxxxxxxxxxx>

Best Regards
Gabriel

On 10/22/21 9:25 AM, Dillon Min wrote:
> Hi Gabriel
>
> I guess you are the maintainer of stm32 clk subsystem from [1], Could
> you help to review this patch, just give a brief of the history:
>
> - this patch was acked by Stephen Boyd at [2].
> - reviewed by Patrice Chotard at [3].
>
> Without this patch , the kernel will turn off ltdc's clk after the
> system reach shell.
>
> [1] https://lore.kernel.org/lkml/AM8PR10MB4785545DC980090C1E7D66B281009@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/
>
> [2] https://lore.kernel.org/linux-arm-kernel/159056850835.88029.9264848839121822798@xxxxxxxxxxxxxxxxxxxxxxxxxx/
>
> [3] https://lore.kernel.org/lkml/6915fa2a-e211-476f-8317-6825e280c322@xxxxxxxxxxx/#t
>
> Best Regards
> Dillon
>
> On Tue, 19 Oct 2021 at 16:44, Dillon Min <dillon.minfei@xxxxxxxxx> wrote:
> > stm32's clk driver register two ltdc gate clk to clk core by
> > clk_hw_register_gate() and clk_hw_register_composite()
> >
> > first: 'stm32f429_gates[]', clk name is 'ltdc', which no user to use.
> > second: 'stm32f429_aux_clk[]', clk name is 'lcd-tft', used by ltdc driver
> >
> > both of them point to the same offset of stm32's RCC register. after
> > kernel enter console, clk core turn off ltdc's clk as 'stm32f429_gates[]'
> > is no one to use. but, actually 'stm32f429_aux_clk[]' is in use.
> >
> > stm32f469/746/769 have the same issue, fix it.
> >
> > Fixes: daf2d117cbca ("clk: stm32f4: Add lcd-tft clock")
> > Acked-by: Stephen Boyd <sboyd@xxxxxxxxxx>
> > Link: https://lore.kernel.org/linux-arm-kernel/1590564453-24499-7-git-send-email-dillon.minfei@xxxxxxxxx/
> > Link: https://lore.kernel.org/lkml/CAPTRvHkf0cK_4ZidM17rPo99gWDmxgqFt4CDUjqFFwkOeQeFDg@xxxxxxxxxxxxxx/
> > Signed-off-by: Dillon Min <dillon.minfei@xxxxxxxxx>
> > ---
> > v6: no change.
> >
> >   drivers/clk/clk-stm32f4.c | 4 ----
> >   1 file changed, 4 deletions(-)
> >
> > diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
> > index af46176ad053..473dfe632cc5 100644
> > --- a/drivers/clk/clk-stm32f4.c
> > +++ b/drivers/clk/clk-stm32f4.c
> > @@ -129,7 +129,6 @@ static const struct stm32f4_gate_data stm32f429_gates[] __initconst = {
> >          { STM32F4_RCC_APB2ENR, 20,      "spi5",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 21,      "spi6",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 22,      "sai1",         "apb2_div" },
> > -       { STM32F4_RCC_APB2ENR, 26,      "ltdc",         "apb2_div" },
> >   };
> >
> >   static const struct stm32f4_gate_data stm32f469_gates[] __initconst = {
> > @@ -211,7 +210,6 @@ static const struct stm32f4_gate_data stm32f469_gates[] __initconst = {
> >          { STM32F4_RCC_APB2ENR, 20,      "spi5",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 21,      "spi6",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 22,      "sai1",         "apb2_div" },
> > -       { STM32F4_RCC_APB2ENR, 26,      "ltdc",         "apb2_div" },
> >   };
> >
> >   static const struct stm32f4_gate_data stm32f746_gates[] __initconst = {
> > @@ -286,7 +284,6 @@ static const struct stm32f4_gate_data stm32f746_gates[] __initconst = {
> >          { STM32F4_RCC_APB2ENR, 21,      "spi6",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 22,      "sai1",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 23,      "sai2",         "apb2_div" },
> > -       { STM32F4_RCC_APB2ENR, 26,      "ltdc",         "apb2_div" },
> >   };
> >
> >   static const struct stm32f4_gate_data stm32f769_gates[] __initconst = {
> > @@ -364,7 +361,6 @@ static const struct stm32f4_gate_data stm32f769_gates[] __initconst = {
> >          { STM32F4_RCC_APB2ENR, 21,      "spi6",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 22,      "sai1",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 23,      "sai2",         "apb2_div" },
> > -       { STM32F4_RCC_APB2ENR, 26,      "ltdc",         "apb2_div" },
> >          { STM32F4_RCC_APB2ENR, 30,      "mdio",         "apb2_div" },
> >   };
> >
> > --
> > 2.7.4