While switching from higher OPP to lower OPP,
current scale logic can fail by switching to lower
voltage while frequency remains at old value.
This patch adds a cleaner recovery logic and
additional freq dpll checks. This changes
program_freq_opp return type in the process
for program_opp to handle error in a consistent
manner.
Tested on:rx-51, ported to pm branch - untested linux-omap
Patch generated on linux-omap pm branch, commit:
7e7377395d6b4576341a6939bf2179f3946f2ea0
Signed-off-by: Nishanth Menon <nm@xxxxxx>
---
arch/arm/mach-omap2/resource34xx.c | 52 +++++++++++++++++++++++++++++-------
1 files changed, 42 insertions(+), 10 deletions(-)
diff --git a/arch/arm/mach-omap2/resource34xx.c b/arch/arm/mach-omap2/resource34xx.c
index 25535a3..1ceaed8 100644
--- a/arch/arm/mach-omap2/resource34xx.c
+++ b/arch/arm/mach-omap2/resource34xx.c
@@ -240,13 +240,23 @@ static int program_opp_freq(int res, int target_level, int current_level)
lock_scratchpad_sem();
if (res == VDD1_OPP) {
curr_opp = &curr_vdd1_opp;
- clk_set_rate(dpll1_clk, mpu_opps[target_level].rate);
- clk_set_rate(dpll2_clk, dsp_opps[target_level].rate);
+ ret = clk_set_rate(dpll1_clk, mpu_opps[target_level].rate);
+ if (unlikely(ret))
+ return ret;
+
+ ret = clk_set_rate(dpll2_clk, dsp_opps[target_level].rate);
+ if (unlikely(ret))
+ /* reset the dpll1 if failed */
+ clk_set_rate(dpll1_clk, mpu_opps[current_level].rate);
#ifndef CONFIG_CPU_FREQ
- /*Update loops_per_jiffy if processor speed is being changed*/
- loops_per_jiffy = compute_lpj(loops_per_jiffy,
- mpu_opps[current_level].rate/1000,
- mpu_opps[target_level].rate/1000);
+ else
+ /*
+ * Update loops_per_jiffy if processor speed
+ * is being changed
+ */
+ loops_per_jiffy = compute_lpj(loops_per_jiffy,
+ mpu_opps[current_level].rate/1000,
+ mpu_opps[target_level].rate/1000);
#endif
} else {
curr_opp = &curr_vdd2_opp;
@@ -257,7 +267,7 @@ static int program_opp_freq(int res, int target_level, int current_level)
}
if (ret) {
unlock_scratchpad_sem();
- return current_level;
+ return ret;
}
#ifdef CONFIG_PM
omap3_save_scratchpad_contents();
@@ -265,7 +275,7 @@ static int program_opp_freq(int res, int target_level, int current_level)
unlock_scratchpad_sem();
*curr_opp = target_level;
- return target_level;
+ return ret;
}
static int program_opp(int res, struct omap_opp *opp, int target_level,
@@ -289,13 +299,35 @@ static int program_opp(int res, struct omap_opp *opp, int target_level,
current_level);
#ifdef CONFIG_OMAP_SMARTREFLEX
else
- sr_voltagescale_vcbypass(t_opp, c_opp,
+ ret = sr_voltagescale_vcbypass(t_opp, c_opp,
opp[target_level].vsel,
opp[current_level].vsel);
+ if (ret) {
+ int ret1 = 0;
+ /*
+ * If something did not work, put me back to old state.
+ * Recover the other guy if at least 1 prev iteration
+ * had run
+ */
+ if (i && raise)
+ ret1 = sr_voltagescale_vcbypass(c_opp, t_opp,
+ opp[current_level].vsel,
+ opp[target_level].vsel);
+ else if (i)
+ ret1 = program_opp_freq(res, current_level,
+ target_level);
+ /*
+ * If I could not reset my old state back.. system
+ * is no longer in a controlled state.. bug me
+ */
+ if (unlikely(ret1))
+ BUG();
+ break;
+ }
#endif
}
- return ret;
+ return (res == PRCM_VDD1) ? curr_vdd1_opp : curr_vdd2_opp;
}
int resource_set_opp_level(int res, u32 target_level, int flags)
--
1.5.4.3
--
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