| Message ID | 20180213134032.30235-2-a.hajda@samsung.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Tue, Feb 13, 2018 at 2:40 PM, Andrzej Hajda <a.hajda@samsung.com> wrote: > Declared rates did not match rates generated by PLL. > As a result driver behaved inconsitently. > > Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> > --- > drivers/clk/samsung/clk-exynos3250.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) How about marking these cc-stable and adding fixes tag? Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2018년 02월 13일 22:40, Andrzej Hajda wrote: > Declared rates did not match rates generated by PLL. > As a result driver behaved inconsitently. > > Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> > --- > drivers/clk/samsung/clk-exynos3250.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/samsung/clk-exynos3250.c b/drivers/clk/samsung/clk-exynos3250.c > index 1b81e283f605..ed36728424a2 100644 > --- a/drivers/clk/samsung/clk-exynos3250.c > +++ b/drivers/clk/samsung/clk-exynos3250.c > @@ -698,7 +698,7 @@ static const struct samsung_pll_rate_table exynos3250_epll_rates[] __initconst = > PLL_36XX_RATE(144000000, 96, 2, 3, 0), > PLL_36XX_RATE( 96000000, 128, 2, 4, 0), > PLL_36XX_RATE( 84000000, 112, 2, 4, 0), > - PLL_36XX_RATE( 80000004, 106, 2, 4, 43691), > + PLL_36XX_RATE( 80000003, 106, 2, 4, 43691), > PLL_36XX_RATE( 73728000, 98, 2, 4, 19923), > PLL_36XX_RATE( 67737598, 270, 3, 5, 62285), > PLL_36XX_RATE( 65535999, 174, 2, 5, 49982), > @@ -734,7 +734,7 @@ static const struct samsung_pll_rate_table exynos3250_vpll_rates[] __initconst = > PLL_36XX_RATE(148352005, 98, 2, 3, 59070), > PLL_36XX_RATE(108000000, 144, 2, 4, 0), > PLL_36XX_RATE( 74250000, 99, 2, 4, 0), > - PLL_36XX_RATE( 74176002, 98, 3, 4, 59070), > + PLL_36XX_RATE( 74176002, 98, 2, 4, 59070), > PLL_36XX_RATE( 54054000, 216, 3, 5, 14156), > PLL_36XX_RATE( 54000000, 144, 2, 5, 0), > { /* sentinel */ } > Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
On 02/13/2018 03:41 PM, Krzysztof Kozlowski wrote: > On Tue, Feb 13, 2018 at 2:40 PM, Andrzej Hajda <a.hajda@samsung.com> wrote: >> Declared rates did not match rates generated by PLL. >> As a result driver behaved inconsitently. >> >> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> >> --- >> drivers/clk/samsung/clk-exynos3250.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) > > How about marking these cc-stable and adding fixes tag? It may potentially cause regressions so I would rather not back port it to older kernels. This applies to all patches in this series, except 7/7.
On Fri, Feb 16, 2018 at 11:00 AM, Sylwester Nawrocki <s.nawrocki@samsung.com> wrote: > On 02/13/2018 03:41 PM, Krzysztof Kozlowski wrote: >> On Tue, Feb 13, 2018 at 2:40 PM, Andrzej Hajda <a.hajda@samsung.com> wrote: >>> Declared rates did not match rates generated by PLL. >>> As a result driver behaved inconsitently. >>> >>> Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> >>> --- >>> drivers/clk/samsung/clk-exynos3250.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> How about marking these cc-stable and adding fixes tag? > > It may potentially cause regressions so I would rather not back port it > to older kernels. This applies to all patches in this series, except 7/7. Hm, existing (old) values were more-or-less tested already, so indeed sounds reasonable. BR, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 02/13/2018 02:40 PM, Andrzej Hajda wrote: > Declared rates did not match rates generated by PLL. > As a result driver behaved inconsitently. How about changing commit message to something along the lines of: "Rates declared in PLL rate tables should match exactly rates calculated from PLL coefficients. If that is not the case, rate of parent might be being set not as expected. For instance, if in the PLL rates table we have a 393216000 Hz entry and the real value as returned by the PLL's recalc_rate callback is 393216003, after setting PLL's clk rate to 393216000 clk_get_rate will return 393216003. If we now attempt to set rate of a PLL's child divider clock to 393216000/2 its rate will be 131072001, rather than 196608000. That is the divider will be set to 3 instead of 2, because 393216003/2 is greater than 196608000. To fix this issue declared rates are changed to exactly match rates generated by a PLL, as calculated from the P, M, S, K coefficients. In this patch an erroneous P value for 74176002 output frequency is also corrected." I would do this also for patches 2...6/7 before applying. -- Thanks, Sylwester -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 02/16/2018 12:58 PM, Sylwester Nawrocki wrote: > On 02/13/2018 02:40 PM, Andrzej Hajda wrote: >> Declared rates did not match rates generated by PLL. >> As a result driver behaved inconsitently. > > How about changing commit message to something along the lines of: > > "Rates declared in PLL rate tables should match exactly rates calculated > from PLL coefficients. If that is not the case, rate of parent might be being s/parent/PLL's child clock > set not as expected. For instance, if in the PLL rates table we have > a 393216000 Hz entry and the real value as returned by the PLL's recalc_rate > callback is 393216003, after setting PLL's clk rate to 393216000 clk_get_rate > will return 393216003. If we now attempt to set rate of a PLL's child divider > clock to 393216000/2 its rate will be 131072001, rather than 196608000. > That is the divider will be set to 3 instead of 2, because 393216003/2 is > greater than 196608000. > > To fix this issue declared rates are changed to exactly match rates generated > by a PLL, as calculated from the P, M, S, K coefficients. > > In this patch an erroneous P value for 74176002 output frequency is also > corrected. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/clk/samsung/clk-exynos3250.c b/drivers/clk/samsung/clk-exynos3250.c index 1b81e283f605..ed36728424a2 100644 --- a/drivers/clk/samsung/clk-exynos3250.c +++ b/drivers/clk/samsung/clk-exynos3250.c @@ -698,7 +698,7 @@ static const struct samsung_pll_rate_table exynos3250_epll_rates[] __initconst = PLL_36XX_RATE(144000000, 96, 2, 3, 0), PLL_36XX_RATE( 96000000, 128, 2, 4, 0), PLL_36XX_RATE( 84000000, 112, 2, 4, 0), - PLL_36XX_RATE( 80000004, 106, 2, 4, 43691), + PLL_36XX_RATE( 80000003, 106, 2, 4, 43691), PLL_36XX_RATE( 73728000, 98, 2, 4, 19923), PLL_36XX_RATE( 67737598, 270, 3, 5, 62285), PLL_36XX_RATE( 65535999, 174, 2, 5, 49982), @@ -734,7 +734,7 @@ static const struct samsung_pll_rate_table exynos3250_vpll_rates[] __initconst = PLL_36XX_RATE(148352005, 98, 2, 3, 59070), PLL_36XX_RATE(108000000, 144, 2, 4, 0), PLL_36XX_RATE( 74250000, 99, 2, 4, 0), - PLL_36XX_RATE( 74176002, 98, 3, 4, 59070), + PLL_36XX_RATE( 74176002, 98, 2, 4, 59070), PLL_36XX_RATE( 54054000, 216, 3, 5, 14156), PLL_36XX_RATE( 54000000, 144, 2, 5, 0), { /* sentinel */ }
Declared rates did not match rates generated by PLL. As a result driver behaved inconsitently. Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> --- drivers/clk/samsung/clk-exynos3250.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)