Re: [PATCH v3 02/28] clk: sunxi-ng: Adjust MP clock parent rate when allowed

Jernej Škrabec
2019-01-18T21:51:10Z

Dne četrtek, 17. januar 2019 ob 08:24:02 CET je Priit Laes napisal(a):
> On Wed, Jan 16, 2019 at 06:00:32PM +0100, Jernej Škrabec wrote:
> > Dne sreda, 16. januar 2019 ob 13:09:58 CET je Priit Laes napisal(a):
> > > On Thu, Jan 10, 2019 at 06:10:59PM +0100, Jernej Škrabec wrote:
> > > > Dne četrtek, 10. januar 2019 ob 10:15:48 CET je Priit Laes napisal(a):
> > > > > On Sun, Nov 04, 2018 at 07:26:39PM +0100, Jernej Skrabec wrote:
> > > > > > Currently MP clocks don't consider adjusting parent rate even if
> > > > > > they
> > > > > > are allowed to do so. Such behaviour considerably lowers amount of
> > > > > > possible rates, which is very inconvenient when such clock is used
> > > > > > for
> > > > > > pixel clock, for example.
> > > > > >
> > > > > > In order to improve the situation, adjusting parent rate is
> > > > > > considered
> > > > > > when allowed.
> > > > > >
> > > > > > This code is inspired by clk_divider_bestdiv() function, which
> > > > > > does
> > > > > > basically the same thing for different clock type.
> > > > >
> > > > > This patch seems to break the eMMC support on Olinuxino-Lime2-eMMC
> > > > > boards:
> > > > >
> > > > > EXT4-fs (mmcblk1p4): INFO: recovery required on readonly filesystem
> > > > > EXT4-fs (mmcblk1p4): write access will be enabled during recovery
> > > > > sunxi-mmc 1c11000.mmc: data error, sending stop command
> > > > > sunxi-mmc 1c11000.mmc: send stop command failed
> > > >
> > > > I'm not familiar with A20. What is interesting is that emmc clocks
> > > > don't
> > > > have CLK_SET_RATE_PARENT flag set, so you shouldn't see any
> > > > difference.
> > > >
> > > > Can you post content of clk_summary with and without this patch?
> > >
> > > In both cases I booted from FEL with rootfs on sdcard and tried to mount
> > > partition from eMMC to /mnt. With your patch, last step it fails.
> > >
> > > pre-patch working:
> > > pll-ddr-other[768MHz] -> mmc2[512MHz]. (For some reason ahb-mmc2 is
> > > off?)
> > >
> > > post-patch not working:
> > > pll-periph[600MHz] -> mmc2[500Mhz], (ahb-mmc2 is enabled)
> > >
> > > Also, attached the logs.
> >
> > Thanks. Just one more request. Can you enable debug messages in mmc
> > driver?
> > I'm interested in output of this line:
> >
> > dev_dbg(mmc_dev(mmc), "setting clk to %d, rounded %ld\n",
> >
> > clock, rate);
>
> 1c11000 is eMMC:
> [snip]
> [ 1.961644] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.004091] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.020296] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.039917] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.047847] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.055053] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.065256] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.092351] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.168725] sunxi-mmc 1c11000.mmc: setting clk to 400000, rounded 400000
> [ 2.189403] sunxi-mmc 1c11000.mmc: setting clk to 52000000, rounded
> 52000000 [ 2.203340] sunxi-mmc 1c11000.mmc: setting clk to 52000000,
> rounded 52000000 [ 2.211412] sunxi-mmc 1c11000.mmc: setting clk to
> 52000000, rounded 52000000 [ 4.967865] sunxi-mmc 1c11000.mmc: setting
> clk to 52000000, rounded 52000000 [ 8.755345] sunxi-mmc 1c11000.mmc:
> setting clk to 52000000, rounded 52000000 [ 9.082510] sunxi-mmc
> 1c11000.mmc: setting clk to 52000000, rounded 52000000
>
> Here I tried to mount partition from eMMC...
>
> [ 72.167311] sunxi-mmc 1c11000.mmc: setting clk to 52000000, rounded
> 52000000 [ 72.269629] sunxi-mmc 1c11000.mmc: data error, sending stop
> command [ 73.268999] sunxi-mmc 1c11000.mmc: send stop command failed
> [/snip]
>
> And clock tree:
> [snip]
> pll-periph-base 3 3 0 1200000000 0
> 0 50000 pll-periph 6 6 0 600000000
> 0 0 50000 mmc2 3 3 0 50000000
> 0 0 50000 mmc2_sample 1 1 0
> 50000000 0 120 50000 mmc2_output 1 1 0
> 50000000 0 60 50000 ahb 18 18
> 0 300000000 0 0 50000 ahb-mmc2 1 1
> 0 300000000 0 0 50000 [/snip]
>
>
> And without patch:
> [snip]
> [ 2.003341] sunxi-mmc 1c11000.mmc: XXX: setting clk to 400000, rounded
> 400000 [ 2.019479] sunxi-mmc 1c11000.mmc: XXX: setting clk to 400000,
> rounded 400000 [ 2.039144] sunxi-mmc 1c11000.mmc: XXX: setting clk to
> 400000, rounded 400000 [ 2.047129] sunxi-mmc 1c11000.mmc: XXX: setting
> clk to 400000, rounded 400000 [ 2.054324] sunxi-mmc 1c11000.mmc: XXX:
> setting clk to 400000, rounded 400000 [ 2.064481] sunxi-mmc 1c11000.mmc:
> XXX: setting clk to 400000, rounded 400000 [ 2.091624] sunxi-mmc
> 1c11000.mmc: XXX: setting clk to 400000, rounded 400000 [ 2.168067]
> sunxi-mmc 1c11000.mmc: XXX: setting clk to 400000, rounded 400000 [
> 2.188239] sunxi-mmc 1c11000.mmc: XXX: setting clk to 52000000, rounded
> 51200000 [ 2.202779] sunxi-mmc 1c11000.mmc: XXX: setting clk to
> 52000000, rounded 51200000 [ 2.210817] sunxi-mmc 1c11000.mmc: XXX:
> setting clk to 52000000, rounded 51200000 [ 5.103358] sunxi-mmc
> 1c11000.mmc: XXX: setting clk to 52000000, rounded 51200000 [ 8.950237]
> sunxi-mmc 1c11000.mmc: XXX: setting clk to 52000000, rounded 51200000 [
> 9.376201] sunxi-mmc 1c11000.mmc: XXX: setting clk to 52000000, rounded
> 51200000 [ 113.618387] sunxi-mmc 1c11000.mmc: XXX: setting clk to
> 52000000, rounded 51200000 [ 113.707979] EXT4-fs (mmcblk1p4): recovery
> complete
> [ 113.728162] EXT4-fs (mmcblk1p4): mounted filesystem with ordered data
> mode. Opts: (null) [/snip]
>
> And clock tree:
> [snip]
> pll-ddr-base 2 2 0 768000000 0
> 0 50000 pll-ddr-other 1 1 0 768000000
> 0 0 50000 mmc2 0 0 0 51200000
> 0 0 50000 mmc2_sample 0 0 0
> 51200000 0 120 50000 mmc2_output 0 0 0
> 51200000 0 72 50000 [/snip]
>

It seems to me that clock rate is set properly. It's even better than before
since there is no error between wanted and real clock. I bet that if you call
clk_get_rate() directly behind clk_set_rate() in mmc driver, you'll get
correct value.

However, it seems that at some point some other peripheral changes it's parent
clock rate, which inadvertely changes emmc2 clock rate too. The only possible
clock which could interfere is sata. Can you disable driver in you kernel
config and try again?

Best regards,
Jernej

> > Just wondering what it should be.
> >
> > Best regards,
> > Jernej
> >
> > > > Best regards,
> > > > Jernej
> > > >
> > > > > $ git bisect log
> > > > > git bisect start
> > > > > # good: [3df407b2a5346db1c48809706ece7a8616c79e0b] mmc:
> > > > > dw_mmc-bluefield:
> > > > > simplify the probe() function git bisect good
> > > > > 3df407b2a5346db1c48809706ece7a8616c79e0b
> > > > > # bad: [00d59fde8532b2d42e80909d2e58678755e04da9] Merge tag
> > > > > 'mmc-v4.21'
> > > > > of
> > > > > git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc git bisect
> > > > > bad
> > > > > 00d59fde8532b2d42e80909d2e58678755e04da9
> > > > > # good: [01e421feec0817bb3141eaae4c517410d193d440] Merge branch
> > > > > 'fixes'
> > > > > into next git bisect good 01e421feec0817bb3141eaae4c517410d193d440
> > > > > # bad: [1eefdec18eded41833401cfd64749643ff72e7da] Merge branch
> > > > > 'locking-core-for-linus' of
> > > > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect bad
> > > > > 1eefdec18eded41833401cfd64749643ff72e7da
> > > > > # good: [eaa76499711535fd64d747cc4ef0d78ab0fd41c6] Merge tag
> > > > > 'mtd/for-4.21'
> > > > > of git://git.infradead.org/linux-mtd git bisect good
> > > > > eaa76499711535fd64d747cc4ef0d78ab0fd41c6
> > > > > # good: [4e4390ad067a61ce4e7607bd0df31f19a4caa36a] Merge tag
> > > > > 'leds-for-4.21-rc1' of
> > > > > git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-led
> > > > > s
> > > > > git
> > > > > bisect good 4e4390ad067a61ce4e7607bd0df31f19a4caa36a
> > > > > # bad: [c2f1f3e0e17d94ab0c66d83e669492cb9e9a3698] Merge
> > > > > git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next git
> > > > > bisect
> > > > > bad c2f1f3e0e17d94ab0c66d83e669492cb9e9a3698
> > > > > # bad: [e4b99d415c3908581d4703203e1e805f043a3e71] Merge branch
> > > > > 'irq-core-for-linus' of
> > > > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip git bisect bad
> > > > > e4b99d415c3908581d4703203e1e805f043a3e71
> > > > > # bad: [ffe05540d18013db62c43627836a3638e9a2c7aa] Merge branches
> > > > > 'clk-renesas', 'clk-allwinner', 'clk-tegra', 'clk-meson' and
> > > > > 'clk-rockchip'
> > > > > into clk-next git bisect bad
> > > > > ffe05540d18013db62c43627836a3638e9a2c7aa
> > > > > # good: [1a501c8defe950571316d5ddd917bf44f5ed7bd4] Merge branches
> > > > > 'clk-managed-registration', 'clk-spdx', 'clk-remove-basic' and
> > > > > 'clk-ops-const' into clk-next git bisect good
> > > > > 1a501c8defe950571316d5ddd917bf44f5ed7bd4
> > > > > # good: [e74581b79ddd9b49b8c61e2791fc4dffc0245afb] Merge tag
> > > > > 'meson-clk-4.21-2' of https://github.com/BayLibre/clk-meson into
> > > > > clk-meson
> > > > > git bisect good e74581b79ddd9b49b8c61e2791fc4dffc0245afb
> > > > > # good: [60baf75e3f5b76043c25328ac0c5320aaef5ea41] Merge tag
> > > > > 'clk-renesas-for-v4.21-tag2' of
> > > > > git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers
> > > > > into
> > > > > clk-renesas git bisect good 60baf75e3f5b76043c25328ac0c5320aaef5ea41
> > > > > # bad: [a41f85b6017ee20952a60e4330bcae2527fe2c2a] Merge tag
> > > > > 'sunxi-clk-for-4.21' of
> > > > > https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into
> > > > > clk-allwinner git bisect bad
> > > > > a41f85b6017ee20952a60e4330bcae2527fe2c2a
> > > > > # bad: [ee678706e46d0d185c27cc214ad97828e0643159] clk: sunxi-ng:
> > > > > a64:
> > > > > Fix
> > > > > gate bit of DSI DPHY git bisect bad
> > > > > ee678706e46d0d185c27cc214ad97828e0643159
> > > > > # bad: [65b6657672388b72822e0367f06d41c1e3ffb5bb] clk: sunxi-ng: Use
> > > > > u64
> > > > > for calculation of NM rate git bisect bad
> > > > > 65b6657672388b72822e0367f06d41c1e3ffb5bb
> > > > > # good: [db7548934603d9eda12649dff97ea5c29884405d] clk: sunxi-ng:
> > > > > sun50i:
> > > > > h6: Fix MMC clock mux width git bisect good
> > > > > db7548934603d9eda12649dff97ea5c29884405d
> > > > > # bad: [3f790433c3cb27ecaf2ca0e07ac25964e4fd9f15] clk: sunxi-ng:
> > > > > Adjust
> > > > > MP
> > > > > clock parent rate when allowed git bisect bad
> > > > > 3f790433c3cb27ecaf2ca0e07ac25964e4fd9f15
> > > > > # first bad commit: [3f790433c3cb27ecaf2ca0e07ac25964e4fd9f15] clk:
> > > > > sunxi-ng: Adjust MP clock parent rate when allowed
> > > > >
> > > > > > Signed-off-by: Jernej Skrabec <jernej.skrabec-gGgVlfcn5nU@public.gmane.org>
> > > > > > ---
> > > > > >
> > > > > > drivers/clk/sunxi-ng/ccu_mp.c | 64
> > > > > > +++++++++++++++++++++++++++++++++--
> > > > > > 1 file changed, 62 insertions(+), 2 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/clk/sunxi-ng/ccu_mp.c
> > > > > > b/drivers/clk/sunxi-ng/ccu_mp.c
> > > > > > index 5d0af4051737..0357349eb767 100644
> > > > > > --- a/drivers/clk/sunxi-ng/ccu_mp.c
> > > > > > +++ b/drivers/clk/sunxi-ng/ccu_mp.c
> > > > > > @@ -40,6 +40,61 @@ static void ccu_mp_find_best(unsigned long
> > > > > > parent,
> > > > > > unsigned long rate,>
> > > > > >
> > > > > > *p = best_p;
> > > > > >
> > > > > > }
> > > > > >
> > > > > > +static unsigned long ccu_mp_find_best_with_parent_adj(struct
> > > > > > clk_hw
> > > > > > *hw,
> > > > > > +
> > > >
> > > > unsigned long *parent,
> > > >
> > > > > > +
> > > >
> > > > unsigned long rate,
> > > >
> > > > > > +
> > > >
> > > > unsigned int max_m,
> > > >
> > > > > > +
> > > >
> > > > unsigned int max_p)
> > > >
> > > > > > +{
> > > > > > + unsigned long parent_rate_saved;
> > > > > > + unsigned long parent_rate, now;
> > > > > > + unsigned long best_rate = 0;
> > > > > > + unsigned int _m, _p, div;
> > > > > > + unsigned long maxdiv;
> > > > > > +
> > > > > > + parent_rate_saved = *parent;
> > > > > > +
> > > > > > + /*
> > > > > > + * The maximum divider we can use without overflowing
> > > > > > + * unsigned long in rate * m * p below
> > > > > > + */
> > > > > > + maxdiv = max_m * max_p;
> > > > > > + maxdiv = min(ULONG_MAX / rate, maxdiv);
> > > > > > +
> > > > > > + for (_p = 1; _p <= max_p; _p <<= 1) {
> > > > > > + for (_m = 1; _m <= max_m; _m++) {
> > > > > > + div = _m * _p;
> > > > > > +
> > > > > > + if (div > maxdiv)
> > > > > > + break;
> > > > > > +
> > > > > > + if (rate * div == parent_rate_saved) {
> > > > > > + /*
> > > > > > + * It's the most ideal case if
> > > >
> > > > the requested
> > > >
> > > > > > + * rate can be divided from
> > > >
> > > > parent clock without
> > > >
> > > > > > + * needing to change parent
> >
> > rate,
> >
> > > > so return the
> > > >
> > > > > > + * divider immediately.
> > > > > > + */
> > > > > > + *parent = parent_rate_saved;
> > > > > > + return rate;
> > > > > > + }
> > > > > > +
> > > > > > + parent_rate = clk_hw_round_rate(hw, rate *
> > > >
> > > > div);
> > > >
> > > > > > + now = parent_rate / div;
> > > > > > +
> > > > > > + if (now <= rate && now > best_rate) {
> > > > > > + best_rate = now;
> > > > > > + *parent = parent_rate;
> > > > > > +
> > > > > > + if (now == rate)
> > > > > > + return rate;
> > > > > > + }
> > > > > > + }
> > > > > > + }
> > > > > > +
> > > > > > + return best_rate;
> > > > > > +}
> > > > > > +
> > > > > >
> > > > > > static unsigned long ccu_mp_round_rate(struct ccu_mux_internal
> > > > > > *mux,
> > > > > >
> > > > > > struct clk_hw *hw,
> > > > > > unsigned long
> > > >
> > > > *parent_rate,
> > > >
> > > > > > @@ -56,8 +111,13 @@ static unsigned long ccu_mp_round_rate(struct
> > > > > > ccu_mux_internal *mux,>
> > > > > >
> > > > > > max_m = cmp->m.max ?: 1 << cmp->m.width;
> > > > > > max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);
> > > > > >
> > > > > > - ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p);
> > > > > > - rate = *parent_rate / p / m;
> > > > > > + if (!(clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT)) {
> > > > > > + ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m,
> > > >
> > > > &p);
> > > >
> > > > > > + rate = *parent_rate / p / m;
> > > > > > + } else {
> > > > > > + rate = ccu_mp_find_best_with_parent_adj(hw,
> >
> > parent_rate,
> >
> > > > rate,
> > > >
> > > > > > +
> > > >
> > > > max_m, max_p);
> > > >
> > > > > > + }
> > > > > >
> > > > > > if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
> > > > > >
> > > > > > rate /= cmp->fixed_post_div;

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