ext Nishanth Menon wrote:
Rev 2 of the patch:
Ref: http://marc.info/?t=124930700200005&r=1&w=2
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.
NOTE: I moved the *cur_opp setting to under the
scratchpad locked region to allow for code
simplicity - I wonder if anyone sees an issue with it
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 | 61 +++++++++++++++++++++++++++---------
1 files changed, 46 insertions(+), 15 deletions(-)
diff --git a/arch/arm/mach-omap2/resource34xx.c b/arch/arm/mach-omap2/resource34xx.c
index 25535a3..83241c4 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))
+ goto out;
+
+ 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;
@@ -255,17 +265,16 @@ static int program_opp_freq(int res, int target_level, int current_level)
ret = clk_set_rate(dpll3_clk,
l3_opps[target_level].rate * l3_div);
}
- if (ret) {
- unlock_scratchpad_sem();
- return current_level;
- }
+out:
+ if (!ret) {
#ifdef CONFIG_PM
- omap3_save_scratchpad_contents();
+ omap3_save_scratchpad_contents();
+ *curr_opp = target_level;
#endif
shouldn't &curr_opp = target_level be done outside of #ifdef CONFIG_PM?
+ }
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 +298,35 @@ 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)
--
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