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 + } 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) -- 1.5.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
