| Message ID | 1391012648-12481-2-git-send-email-maxime.coquelin@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Quoting Maxime COQUELIN (2014-01-29 08:24:06) > The divider returned by clk_divider_bestdiv() is likely to be invalid in case > of power-of-two and table dividers when CLK_SET_RATE_PARENT flag isn't set. > > Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com> I've taken this into clk-fixes for 3.15-rcX. Thanks, Mike > --- > drivers/clk/clk-divider.c | 37 ++++++++++++++++++++++++++++++++++++- > 1 file changed, 36 insertions(+), 1 deletion(-) > > diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c > index 5543b7d..2137d58 100644 > --- a/drivers/clk/clk-divider.c > +++ b/drivers/clk/clk-divider.c > @@ -144,6 +144,37 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div) > return true; > } > > +static int _round_up_table(const struct clk_div_table *table, int div) > +{ > + const struct clk_div_table *clkt; > + int up = _get_table_maxdiv(table); > + > + for (clkt = table; clkt->div; clkt++) { > + if (clkt->div == div) > + return clkt->div; > + else if (clkt->div < div) > + continue; > + > + if ((clkt->div - div) < (up - div)) > + up = clkt->div; > + } > + > + return up; > +} > + > +static int _div_round_up(struct clk_divider *divider, > + unsigned long parent_rate, unsigned long rate) > +{ > + int div = DIV_ROUND_UP(parent_rate, rate); > + > + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) > + div = __roundup_pow_of_two(div); > + if (divider->table) > + div = _round_up_table(divider->table, div); > + > + return div; > +} > + > static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, > unsigned long *best_parent_rate) > { > @@ -159,7 +190,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, > > if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) { > parent_rate = *best_parent_rate; > - bestdiv = DIV_ROUND_UP(parent_rate, rate); > + bestdiv = _div_round_up(divider, parent_rate, rate); > bestdiv = bestdiv == 0 ? 1 : bestdiv; > bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv; > return bestdiv; > @@ -219,6 +250,10 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate, > u32 val; > > div = parent_rate / rate; > + > + if (!_is_valid_div(divider, div)) > + return -EINVAL; > + > value = _get_val(divider, div); > > if (value > div_mask(divider)) > -- > 1.7.9.5 >
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 5543b7d..2137d58 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -144,6 +144,37 @@ static bool _is_valid_div(struct clk_divider *divider, unsigned int div) return true; } +static int _round_up_table(const struct clk_div_table *table, int div) +{ + const struct clk_div_table *clkt; + int up = _get_table_maxdiv(table); + + for (clkt = table; clkt->div; clkt++) { + if (clkt->div == div) + return clkt->div; + else if (clkt->div < div) + continue; + + if ((clkt->div - div) < (up - div)) + up = clkt->div; + } + + return up; +} + +static int _div_round_up(struct clk_divider *divider, + unsigned long parent_rate, unsigned long rate) +{ + int div = DIV_ROUND_UP(parent_rate, rate); + + if (divider->flags & CLK_DIVIDER_POWER_OF_TWO) + div = __roundup_pow_of_two(div); + if (divider->table) + div = _round_up_table(divider->table, div); + + return div; +} + static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, unsigned long *best_parent_rate) { @@ -159,7 +190,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw, unsigned long rate, if (!(__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT)) { parent_rate = *best_parent_rate; - bestdiv = DIV_ROUND_UP(parent_rate, rate); + bestdiv = _div_round_up(divider, parent_rate, rate); bestdiv = bestdiv == 0 ? 1 : bestdiv; bestdiv = bestdiv > maxdiv ? maxdiv : bestdiv; return bestdiv; @@ -219,6 +250,10 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate, u32 val; div = parent_rate / rate; + + if (!_is_valid_div(divider, div)) + return -EINVAL; + value = _get_val(divider, div); if (value > div_mask(divider))
The divider returned by clk_divider_bestdiv() is likely to be invalid in case of power-of-two and table dividers when CLK_SET_RATE_PARENT flag isn't set. Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com> --- drivers/clk/clk-divider.c | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-)