Thread (45 messages) 45 messages, 3 authors, 2019-03-19

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

From: Jernej Škrabec <hidden>
Date: 2019-01-18 21:51:25
Also in: dri-devel, linux-clk, linux-devicetree, lkml

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:
quoted
Dne sreda, 16. januar 2019 ob 13:09:58 CET je Priit Laes napisal(a):
quoted
On Thu, Jan 10, 2019 at 06:10:59PM +0100, Jernej Škrabec wrote:
quoted
Dne četrtek, 10. januar 2019 ob 10:15:48 CET je Priit Laes napisal(a):
quoted
On Sun, Nov 04, 2018 at 07:26:39PM +0100, Jernej Skrabec wrote:
quoted
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
quoted
Just wondering what it should be.

Best regards,
Jernej
quoted
quoted
Best regards,
Jernej
quoted
$ 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
quoted
Signed-off-by: Jernej Skrabec <redacted>
---

 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,
quoted
quoted
+
unsigned long rate,
quoted
quoted
+
unsigned int max_m,
quoted
quoted
+
unsigned int max_p)
quoted
quoted
+{
+	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
quoted
quoted
+				 * rate can be divided from
parent clock without
quoted
quoted
+				 * needing to change parent
rate,
quoted
quoted
so return the
quoted
quoted
+				 * divider immediately.
+				 */
+				*parent = parent_rate_saved;
+				return rate;
+			}
+
+			parent_rate = clk_hw_round_rate(hw, rate *
div);
quoted
quoted
+			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,
quoted
quoted
@@ -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);
quoted
quoted
+		rate = *parent_rate / p / m;
+	} else {
+		rate = ccu_mp_find_best_with_parent_adj(hw,
parent_rate,
quoted
quoted
rate,
quoted
quoted
+
max_m, max_p);
quoted
quoted
+	}

 	if (cmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
 	
 		rate /= cmp->fixed_post_div;




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