[meta-freescale] Warning - rev 3.0.0 kernel for i.MXDL causes kernel breakage on Wandboard (i.mx6 DL)

[John Weber]

I've been working with the rev 1.1.0 kernel (3.0.35) with no problems.  Recent 
merge

http://git.yoctoproject.org/cgit/cgit.cgi/meta-fsl-arm/commit/recipes-kernel/linux/linux-imx_3.0.35.bb?id=33cecc59c6e552a5cc79517e5a80815b18479db9

added SRCREV_mx6dl which moved the Wandboard kernel to rev 3.0.0, which I 
suppose is the one Freescale is using for the Dual Lite.

Now, I'm getting an error during kernel boot during a call to 
regulator_set_voltage():

[<80269c4c>] (regulator_set_voltage+0x8/0xdc) from [<800609c8>] (set_cpu_freq+0x
12c/0x21c)
[<800609c8>] (set_cpu_freq+0x12c/0x21c) from [<80060cd0>] (mxc_set_target+0xf4/0
x220)
[<80060cd0>] (mxc_set_target+0xf4/0x220) from [<8036c0d4>] (__cpufreq_driver_tar
get+0x4c/0x60)
[<8036c0d4>] (__cpufreq_driver_target+0x4c/0x60) from [<803708b0>] (cpufreq_inte
ractive_freq_down+0xf8/0x12c)
[<803708b0>] (cpufreq_interactive_freq_down+0xf8/0x12c) from [<80084854>] (proce
ss_one_work+0x110/0x39c)
[<80084854>] (process_one_work+0x110/0x39c) from [<80084de4>] (worker_thread+0x1
38/0x2f4)
[<80084de4>] (worker_thread+0x138/0x2f4) from [<80089600>] (kthread+0x80/0x88)

Questions - what are the differences between rev 3.0.0 and 1.1.0?
Why are there two separate branches?  Will they be merged eventually so that we 
don't have to work with two?

As far as I can tell, the differences are fairly minimal.  Focusing on anything 
that might be related to the DVFS or regulators, here are the differences:

(- is the rev 1.1.0 kernel, + is rev 3.0.0 kernel)

diff --git a/arch/arm/mach-mx6/cpu_op-mx6.c b/arch/arm/mach-mx6/cpu_op-mx6.c
index e6ef026..028e876 100644
--- a/arch/arm/mach-mx6/cpu_op-mx6.c
+++ b/arch/arm/mach-mx6/cpu_op-mx6.c
@@ -153,8 +153,8 @@ static struct cpu_op mx6dl_cpu_op_1_2G[] = {
  	 .pll_rate = 1200000000,
  	 .cpu_rate = 1200000000,
  	 .cpu_podf = 0,
-	 .pu_voltage = 1275000,
-	 .soc_voltage = 1275000,
+	 .pu_voltage = 1175000,
+	 .soc_voltage = 1175000,
  	 .cpu_voltage = 1275000,},
  	{
  	 .pll_rate = 792000000,
@@ -177,9 +177,9 @@ static struct cpu_op mx6dl_cpu_op_1G[] = {
  	 .pll_rate = 996000000,
  	 .cpu_rate = 996000000,
  	 .cpu_podf = 0,
-	 .pu_voltage = 1275000,
-	 .soc_voltage = 1275000,
-	 .cpu_voltage = 1275000,},
+	 .pu_voltage = 1175000,
+	 .soc_voltage = 1175000,
+	 .cpu_voltage = 1250000,},
  	{
  	 .pll_rate = 792000000,
  	 .cpu_rate = 792000000,
diff --git a/arch/arm/mach-mx6/system.c b/arch/arm/mach-mx6/system.c
index 6ecd51e..6d24f22 100644
--- a/arch/arm/mach-mx6/system.c
+++ b/arch/arm/mach-mx6/system.c
@@ -157,7 +157,7 @@ void mxc_cpu_lp_set(enum mxc_cpu_pwr_mode mode)
  		   * The PUPSCR should include the time it takes for the ARM LDO to
  		   * ramp up.
  		   */
-		__raw_writel(0x202, gpc_base + GPC_PGC_CPU_PUPSCR_OFFSET);
+		__raw_writel(0xf0f, gpc_base + GPC_PGC_CPU_PUPSCR_OFFSET);
  		/* The PDNSCR is a counter that counts in IPG_CLK cycles. This counter
  		  * can be set to minimum values to power down faster.
  		  */