| Message ID | 1593079768-9349-2-git-send-email-claudiu.beznea@microchip.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] clk: at91: remove the checking of parent_name | expand |
On 25/06/2020 13:09:28+0300, Claudiu Beznea wrote: > Return in clk_main_osc_prepare()/clk_main_rc_osc_prepare() if > oscillators are already enabled. > > Fixes: 27cb1c2083373 ("clk: at91: rework main clk implementation") > Fixes: 1bdf02326b71e ("clk: at91: make use of syscon/regmap internally") Is this really a fix? What is the observed issue? > Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> > --- > drivers/clk/at91/clk-main.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) > > diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c > index 37c22667e831..46b4d2131989 100644 > --- a/drivers/clk/at91/clk-main.c > +++ b/drivers/clk/at91/clk-main.c > @@ -74,13 +74,11 @@ static int clk_main_osc_prepare(struct clk_hw *hw) > regmap_read(regmap, AT91_CKGR_MOR, &tmp); > tmp &= ~MOR_KEY_MASK; > > - if (tmp & AT91_PMC_OSCBYPASS) > + if (tmp & (AT91_PMC_OSCBYPASS | AT91_PMC_MOSCEN)) > return 0; While this seems like a good optimization, it is also not correct. Having AT91_PMC_MOSCEN set doesn't mean that the clock is ready, you need to at least check MOSCS once. > > - if (!(tmp & AT91_PMC_MOSCEN)) { > - tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY; > - regmap_write(regmap, AT91_CKGR_MOR, tmp); > - } > + tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY; > + regmap_write(regmap, AT91_CKGR_MOR, tmp); > > while (!clk_main_osc_ready(regmap)) > cpu_relax(); > @@ -186,10 +184,12 @@ static int clk_main_rc_osc_prepare(struct clk_hw *hw) > > regmap_read(regmap, AT91_CKGR_MOR, &mor); > > - if (!(mor & AT91_PMC_MOSCRCEN)) > - regmap_update_bits(regmap, AT91_CKGR_MOR, > - MOR_KEY_MASK | AT91_PMC_MOSCRCEN, > - AT91_PMC_MOSCRCEN | AT91_PMC_KEY); > + if (mor & AT91_PMC_MOSCRCEN) > + return 0; > + > + regmap_update_bits(regmap, AT91_CKGR_MOR, > + MOR_KEY_MASK | AT91_PMC_MOSCRCEN, > + AT91_PMC_MOSCRCEN | AT91_PMC_KEY); > > while (!clk_main_rc_osc_ready(regmap)) > cpu_relax(); > -- > 2.7.4 >
On 27.06.2020 00:03, Alexandre Belloni wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > On 25/06/2020 13:09:28+0300, Claudiu Beznea wrote: >> Return in clk_main_osc_prepare()/clk_main_rc_osc_prepare() if >> oscillators are already enabled. >> >> Fixes: 27cb1c2083373 ("clk: at91: rework main clk implementation") >> Fixes: 1bdf02326b71e ("clk: at91: make use of syscon/regmap internally") > > Is this really a fix? What is the observed issue? > >> Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> >> --- >> drivers/clk/at91/clk-main.c | 18 +++++++++--------- >> 1 file changed, 9 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c >> index 37c22667e831..46b4d2131989 100644 >> --- a/drivers/clk/at91/clk-main.c >> +++ b/drivers/clk/at91/clk-main.c >> @@ -74,13 +74,11 @@ static int clk_main_osc_prepare(struct clk_hw *hw) >> regmap_read(regmap, AT91_CKGR_MOR, &tmp); >> tmp &= ~MOR_KEY_MASK; >> >> - if (tmp & AT91_PMC_OSCBYPASS) >> + if (tmp & (AT91_PMC_OSCBYPASS | AT91_PMC_MOSCEN)) >> return 0; > > While this seems like a good optimization, it is also not correct. > Having AT91_PMC_MOSCEN set doesn't mean that the clock is ready, you > need to at least check MOSCS once. I agree! This is may introduce issues. Thank you for reviewing it. > >> >> - if (!(tmp & AT91_PMC_MOSCEN)) { >> - tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY; >> - regmap_write(regmap, AT91_CKGR_MOR, tmp); >> - } >> + tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY; >> + regmap_write(regmap, AT91_CKGR_MOR, tmp); >> >> while (!clk_main_osc_ready(regmap)) >> cpu_relax(); >> @@ -186,10 +184,12 @@ static int clk_main_rc_osc_prepare(struct clk_hw *hw) >> >> regmap_read(regmap, AT91_CKGR_MOR, &mor); >> >> - if (!(mor & AT91_PMC_MOSCRCEN)) >> - regmap_update_bits(regmap, AT91_CKGR_MOR, >> - MOR_KEY_MASK | AT91_PMC_MOSCRCEN, >> - AT91_PMC_MOSCRCEN | AT91_PMC_KEY); >> + if (mor & AT91_PMC_MOSCRCEN) >> + return 0; >> + >> + regmap_update_bits(regmap, AT91_CKGR_MOR, >> + MOR_KEY_MASK | AT91_PMC_MOSCRCEN, >> + AT91_PMC_MOSCRCEN | AT91_PMC_KEY); >> >> while (!clk_main_rc_osc_ready(regmap)) >> cpu_relax(); >> -- >> 2.7.4 >> > > -- > Alexandre Belloni, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com >
diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c index 37c22667e831..46b4d2131989 100644 --- a/drivers/clk/at91/clk-main.c +++ b/drivers/clk/at91/clk-main.c @@ -74,13 +74,11 @@ static int clk_main_osc_prepare(struct clk_hw *hw) regmap_read(regmap, AT91_CKGR_MOR, &tmp); tmp &= ~MOR_KEY_MASK; - if (tmp & AT91_PMC_OSCBYPASS) + if (tmp & (AT91_PMC_OSCBYPASS | AT91_PMC_MOSCEN)) return 0; - if (!(tmp & AT91_PMC_MOSCEN)) { - tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY; - regmap_write(regmap, AT91_CKGR_MOR, tmp); - } + tmp |= AT91_PMC_MOSCEN | AT91_PMC_KEY; + regmap_write(regmap, AT91_CKGR_MOR, tmp); while (!clk_main_osc_ready(regmap)) cpu_relax(); @@ -186,10 +184,12 @@ static int clk_main_rc_osc_prepare(struct clk_hw *hw) regmap_read(regmap, AT91_CKGR_MOR, &mor); - if (!(mor & AT91_PMC_MOSCRCEN)) - regmap_update_bits(regmap, AT91_CKGR_MOR, - MOR_KEY_MASK | AT91_PMC_MOSCRCEN, - AT91_PMC_MOSCRCEN | AT91_PMC_KEY); + if (mor & AT91_PMC_MOSCRCEN) + return 0; + + regmap_update_bits(regmap, AT91_CKGR_MOR, + MOR_KEY_MASK | AT91_PMC_MOSCRCEN, + AT91_PMC_MOSCRCEN | AT91_PMC_KEY); while (!clk_main_rc_osc_ready(regmap)) cpu_relax();
Return in clk_main_osc_prepare()/clk_main_rc_osc_prepare() if oscillators are already enabled. Fixes: 27cb1c2083373 ("clk: at91: rework main clk implementation") Fixes: 1bdf02326b71e ("clk: at91: make use of syscon/regmap internally") Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> --- drivers/clk/at91/clk-main.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)