mvebu: 5.4 fix DVFS caused random boot crashes

5.10.37 and 5.4.119 introduced a lot of DVFS changes for Armada 37xx from 5.13 kernel.

Unfortunately commit:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/drivers/cpufreq/armada-37xx-cpufreq.c?h=v5.10.37&id=a13b110e7c9e0dc2edcc7a19d4255fc88abd83cc

This patch actually corrects the things so that 1 or 1.2GHz models would actually get scaled to their native frequency.

However, due to a AVS setting voltages too low this will cause random crashes on 1.2GHz models.

So, until a new safe for everybody voltage is agreed on
lets revert the patch.

Fixes: 9d21ecc ("kernel: bump 5.4 to 5.4.119")
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
(cherry picked from commit 080a0b74e3)
This commit is contained in:
Robert Marko 2021-05-19 13:02:31 +02:00 committed by Hauke Mehrtens
parent a52842a8d0
commit d5ea756c3e

View File

@ -0,0 +1,107 @@
From 35639bac13927d1476398b740b11cbed0ee3ddb2 Mon Sep 17 00:00:00 2001
From: Robert Marko <robert.marko@sartura.hr>
Date: Tue, 18 May 2021 13:24:30 +0200
Subject: [PATCH] Revert "cpufreq: armada-37xx: Fix setting TBG parent for load
levels"
This reverts commit a13b110e7c9e0dc2edcc7a19d4255fc88abd83cc.
This patch actually corrects the things so that 1 or 1.2GHz models would
actually get scaled to their native frequency.
However, due to a AVS setting voltages too low this will cause random
crashes on 1.2GHz models.
So, until a new safe for everybody voltage is agreed on
lets revert the patch.
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
---
drivers/cpufreq/armada-37xx-cpufreq.c | 35 +++++++++------------------
1 file changed, 12 insertions(+), 23 deletions(-)
--- a/drivers/cpufreq/armada-37xx-cpufreq.c
+++ b/drivers/cpufreq/armada-37xx-cpufreq.c
@@ -25,10 +25,6 @@
#include "cpufreq-dt.h"
-/* Clk register set */
-#define ARMADA_37XX_CLK_TBG_SEL 0
-#define ARMADA_37XX_CLK_TBG_SEL_CPU_OFF 22
-
/* Power management in North Bridge register set */
#define ARMADA_37XX_NB_L0L1 0x18
#define ARMADA_37XX_NB_L2L3 0x1C
@@ -126,15 +122,10 @@ static struct armada_37xx_dvfs *armada_3
* will be configured then the DVFS will be enabled.
*/
static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base,
- struct regmap *clk_base, u8 *divider)
+ struct clk *clk, u8 *divider)
{
- u32 cpu_tbg_sel;
int load_lvl;
-
- /* Determine to which TBG clock is CPU connected */
- regmap_read(clk_base, ARMADA_37XX_CLK_TBG_SEL, &cpu_tbg_sel);
- cpu_tbg_sel >>= ARMADA_37XX_CLK_TBG_SEL_CPU_OFF;
- cpu_tbg_sel &= ARMADA_37XX_NB_TBG_SEL_MASK;
+ struct clk *parent;
for (load_lvl = 0; load_lvl < LOAD_LEVEL_NR; load_lvl++) {
unsigned int reg, mask, val, offset = 0;
@@ -153,11 +144,6 @@ static void __init armada37xx_cpufreq_dv
mask = (ARMADA_37XX_NB_CLK_SEL_MASK
<< ARMADA_37XX_NB_CLK_SEL_OFF);
- /* Set TBG index, for all levels we use the same TBG */
- val = cpu_tbg_sel << ARMADA_37XX_NB_TBG_SEL_OFF;
- mask = (ARMADA_37XX_NB_TBG_SEL_MASK
- << ARMADA_37XX_NB_TBG_SEL_OFF);
-
/*
* Set cpu divider based on the pre-computed array in
* order to have balanced step.
@@ -176,6 +162,14 @@ static void __init armada37xx_cpufreq_dv
regmap_update_bits(base, reg, mask, val);
}
+
+ /*
+ * Set cpu clock source, for all the level we keep the same
+ * clock source that the one already configured. For this one
+ * we need to use the clock framework
+ */
+ parent = clk_get_parent(clk);
+ clk_set_parent(clk, parent);
}
/*
@@ -401,16 +395,11 @@ static int __init armada37xx_cpufreq_dri
struct platform_device *pdev;
unsigned long freq;
unsigned int cur_frequency, base_frequency;
- struct regmap *nb_clk_base, *nb_pm_base, *avs_base;
+ struct regmap *nb_pm_base, *avs_base;
struct device *cpu_dev;
int load_lvl, ret;
struct clk *clk, *parent;
- nb_clk_base =
- syscon_regmap_lookup_by_compatible("marvell,armada-3700-periph-clock-nb");
- if (IS_ERR(nb_clk_base))
- return -ENODEV;
-
nb_pm_base =
syscon_regmap_lookup_by_compatible("marvell,armada-3700-nb-pm");
@@ -487,7 +476,7 @@ static int __init armada37xx_cpufreq_dri
armada37xx_cpufreq_avs_configure(avs_base, dvfs);
armada37xx_cpufreq_avs_setup(avs_base, dvfs);
- armada37xx_cpufreq_dvfs_setup(nb_pm_base, nb_clk_base, dvfs->divider);
+ armada37xx_cpufreq_dvfs_setup(nb_pm_base, clk, dvfs->divider);
clk_put(clk);
for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR;