| Message ID | 20211209163720.106185-3-nikita@trvn.ru (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Prepare general purpose clocks on msm8916 | expand |
Quoting Nikita Travkin (2021-12-09 08:37:18) > Sometimes calculation of d value may result in 0 because of the > rounding after integer division. This causes the following error: > > [ 113.969689] camss_gp1_clk_src: rcg didn't update its configuration. > [ 113.969754] WARNING: CPU: 3 PID: 35 at drivers/clk/qcom/clk-rcg2.c:122 update_config+0xc8/0xdc > > Make sure that D value is never zero. > > Fixes: 7f891faf596e ("clk: qcom: clk-rcg2: Add support for duty-cycle for RCG") > Signed-off-by: Nikita Travkin <nikita@trvn.ru> > --- > drivers/clk/qcom/clk-rcg2.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c > index 6964cf914b60..fdfd43e2a01b 100644 > --- a/drivers/clk/qcom/clk-rcg2.c > +++ b/drivers/clk/qcom/clk-rcg2.c > @@ -424,6 +424,10 @@ static int clk_rcg2_set_duty_cycle(struct clk_hw *hw, struct clk_duty *duty) > if (d > mask) > d = mask; > > + /* Hardware can't handle d=0, make sure it's at least 1 */ > + if (!d) > + d = 1; Maybe clamp() would be better /* * Check bit widths of 2d. If D is too big reduce duty cycle and * ensure it is non-zero. */ clamp(d, 1, mask); > + > if ((d / 2) > (n - m)) > d = (n - m) * 2; > else if ((d / 2) < (m / 2))
Hi, Stephen Boyd писал(а) 08.01.2022 05:56: > Quoting Nikita Travkin (2021-12-09 08:37:18) >> Sometimes calculation of d value may result in 0 because of the >> rounding after integer division. This causes the following error: >> >> [ 113.969689] camss_gp1_clk_src: rcg didn't update its configuration. >> [ 113.969754] WARNING: CPU: 3 PID: 35 at drivers/clk/qcom/clk-rcg2.c:122 update_config+0xc8/0xdc >> >> Make sure that D value is never zero. >> >> Fixes: 7f891faf596e ("clk: qcom: clk-rcg2: Add support for duty-cycle for RCG") >> Signed-off-by: Nikita Travkin <nikita@trvn.ru> >> --- >> drivers/clk/qcom/clk-rcg2.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c >> index 6964cf914b60..fdfd43e2a01b 100644 >> --- a/drivers/clk/qcom/clk-rcg2.c >> +++ b/drivers/clk/qcom/clk-rcg2.c >> @@ -424,6 +424,10 @@ static int clk_rcg2_set_duty_cycle(struct clk_hw *hw, struct clk_duty *duty) >> if (d > mask) >> d = mask; >> >> + /* Hardware can't handle d=0, make sure it's at least 1 */ >> + if (!d) >> + d = 1; > > Maybe clamp() would be better > > /* > * Check bit widths of 2d. If D is too big reduce duty cycle and > * ensure it is non-zero. > */ > clamp(d, 1, mask); > Yes, this looks nicer, will use it in v2. Thanks for the suggestion! Nikita >> + >> if ((d / 2) > (n - m)) >> d = (n - m) * 2; >> else if ((d / 2) < (m / 2))
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c index 6964cf914b60..fdfd43e2a01b 100644 --- a/drivers/clk/qcom/clk-rcg2.c +++ b/drivers/clk/qcom/clk-rcg2.c @@ -424,6 +424,10 @@ static int clk_rcg2_set_duty_cycle(struct clk_hw *hw, struct clk_duty *duty) if (d > mask) d = mask; + /* Hardware can't handle d=0, make sure it's at least 1 */ + if (!d) + d = 1; + if ((d / 2) > (n - m)) d = (n - m) * 2; else if ((d / 2) < (m / 2))
Sometimes calculation of d value may result in 0 because of the rounding after integer division. This causes the following error: [ 113.969689] camss_gp1_clk_src: rcg didn't update its configuration. [ 113.969754] WARNING: CPU: 3 PID: 35 at drivers/clk/qcom/clk-rcg2.c:122 update_config+0xc8/0xdc Make sure that D value is never zero. Fixes: 7f891faf596e ("clk: qcom: clk-rcg2: Add support for duty-cycle for RCG") Signed-off-by: Nikita Travkin <nikita@trvn.ru> --- drivers/clk/qcom/clk-rcg2.c | 4 ++++ 1 file changed, 4 insertions(+)