| Message ID | 20180105170959.17266-2-jbrunet@baylibre.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/05/2018 11:09 AM, Jerome Brunet wrote: > When a divider clock has CLK_DIVIDER_READ_ONLY set, it means that the > register shall be left un-touched, but it does not mean the clock > should stop rate propagation if CLK_SET_RATE_PARENT is set > > This is properly handled in qcom clk-regmap-divider but it was not in > the generic divider > > Fixes: e6d5e7d90be9 ("clk-divider: Fix READ_ONLY when divider > 1") > Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> > --- > drivers/clk/clk-divider.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c > index b49942b9fe50..a851d3e04c7f 100644 > --- a/drivers/clk/clk-divider.c > +++ b/drivers/clk/clk-divider.c > @@ -348,6 +348,7 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate, > unsigned long *prate) > { > struct clk_divider *divider = to_clk_divider(hw); > + struct clk_hw *hw_parent = clk_hw_get_parent(hw); Very minor suggestion: This could be moved inside the if block since it is only used there. > int bestdiv; > > /* if read only, just return current value */ > @@ -356,6 +357,15 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate, > bestdiv &= div_mask(divider->width); > bestdiv = _get_div(divider->table, bestdiv, divider->flags, > divider->width); > + > + /* Even a read-only clock can propagate a rate change */ > + if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { > + if (!hw_parent) > + return -EINVAL; > + > + *prate = clk_hw_round_rate(hw_parent, rate * bestdiv); > + } > + > return DIV_ROUND_UP_ULL((u64)*prate, bestdiv); > } > > Tested-by: David Lechner <david@lechnology.com>
On Thu, 2018-01-11 at 16:55 -0600, David Lechner wrote: > On 01/05/2018 11:09 AM, Jerome Brunet wrote: > > When a divider clock has CLK_DIVIDER_READ_ONLY set, it means that the > > register shall be left un-touched, but it does not mean the clock > > should stop rate propagation if CLK_SET_RATE_PARENT is set > > > > This is properly handled in qcom clk-regmap-divider but it was not in > > the generic divider > > > > Fixes: e6d5e7d90be9 ("clk-divider: Fix READ_ONLY when divider > 1") > > Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> > > --- > > drivers/clk/clk-divider.c | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c > > index b49942b9fe50..a851d3e04c7f 100644 > > --- a/drivers/clk/clk-divider.c > > +++ b/drivers/clk/clk-divider.c > > @@ -348,6 +348,7 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate, > > unsigned long *prate) > > { > > struct clk_divider *divider = to_clk_divider(hw); > > + struct clk_hw *hw_parent = clk_hw_get_parent(hw); > > Very minor suggestion: This could be moved inside the if block since it is only used there. Even if correct, this is something I have seen done in CCF. I tend to just follow the way to be honest. Stephen, do you have any preference ? > > > int bestdiv; > > > > /* if read only, just return current value */ > > @@ -356,6 +357,15 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate, > > bestdiv &= div_mask(divider->width); > > bestdiv = _get_div(divider->table, bestdiv, divider->flags, > > divider->width); > > + > > + /* Even a read-only clock can propagate a rate change */ > > + if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { > > + if (!hw_parent) > > + return -EINVAL; > > + > > + *prate = clk_hw_round_rate(hw_parent, rate * bestdiv); > > + } > > + > > return DIV_ROUND_UP_ULL((u64)*prate, bestdiv); > > } > > > > > > Tested-by: David Lechner <david@lechnology.com>
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index b49942b9fe50..a851d3e04c7f 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -348,6 +348,7 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { struct clk_divider *divider = to_clk_divider(hw); + struct clk_hw *hw_parent = clk_hw_get_parent(hw); int bestdiv; /* if read only, just return current value */ @@ -356,6 +357,15 @@ static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate, bestdiv &= div_mask(divider->width); bestdiv = _get_div(divider->table, bestdiv, divider->flags, divider->width); + + /* Even a read-only clock can propagate a rate change */ + if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) { + if (!hw_parent) + return -EINVAL; + + *prate = clk_hw_round_rate(hw_parent, rate * bestdiv); + } + return DIV_ROUND_UP_ULL((u64)*prate, bestdiv); }
When a divider clock has CLK_DIVIDER_READ_ONLY set, it means that the register shall be left un-touched, but it does not mean the clock should stop rate propagation if CLK_SET_RATE_PARENT is set This is properly handled in qcom clk-regmap-divider but it was not in the generic divider Fixes: e6d5e7d90be9 ("clk-divider: Fix READ_ONLY when divider > 1") Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> --- drivers/clk/clk-divider.c | 10 ++++++++++ 1 file changed, 10 insertions(+)