[U-Boot] i.MX6 freeze when running Linux FSL 3.10.9-1.0.0-alpha AND U-Boot 2013.10

[Eric Bénard]

Hi Otavio,

Le Tue, 26 Nov 2013 12:32:45 -0200,
Otavio Salvador <otavio at ossystems.com.br> a écrit :

> Hello,
> 
> last days I've been trying to isolate the hung cause of a customer
> board, and also SabreSD board, when using the Freescale's Linux fork
> of 3.10.9 with 2013.10 U-Boot.
> 
> The below patch makes it work fine but it does not seem to be possible
> to upstream this fix, that way. How you guys thing this could be
> properly integrated into U-Boot to not break other boards?
> 
> diff --git a/arch/arm/cpu/armv7/mx6/soc.c b/arch/arm/cpu/armv7/mx6/soc.c
> index a390296..08f3eda 100644
> --- a/arch/arm/cpu/armv7/mx6/soc.c
> +++ b/arch/arm/cpu/armv7/mx6/soc.c
> @@ -131,6 +131,34 @@ static void imx_set_wdog_powerdown(bool enable)
>   writew(enable, &wdog2->wmcr);
>  }
> 
> +static void imx_set_vddpu_power_down(void)
> +{
> + struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
> + u32 val;
> +
> + /* need to power down xPU in GPC before turn off PU LDO */
> + val = readl(GPC_BASE_ADDR + 0x260);
> + writel(val | 0x1, GPC_BASE_ADDR + 0x260);
> +
> + val = readl(GPC_BASE_ADDR + 0x0);
> + writel(val | 0x1, GPC_BASE_ADDR + 0x0);
> + while (readl(GPC_BASE_ADDR + 0x0) & 0x1)
> + ;
> +
> + /* disable VDDPU */
> + val = 0x3e00;
> + writel(val, &anatop->reg_core_clr);
> +}
> +
> +static void imx_set_pcie_phy_power_down(void)
> +{
> + u32 val;
> +
> + val = readl(IOMUXC_BASE_ADDR + 0x4);
> + val |= 0x1 << 18;
> + writel(val, IOMUXC_BASE_ADDR + 0x4);
> +}
> +
>  int arch_cpu_init(void)
>  {
>   init_aips();
> @@ -139,6 +167,9 @@ int arch_cpu_init(void)
> 
>   imx_set_wdog_powerdown(false); /* Disable PDE bit of WMCR register */
> 
> + imx_set_pcie_phy_power_down();
> + imx_set_vddpu_power_down();
> +
>  #ifdef CONFIG_APBH_DMA
>   /* Start APBH DMA */
>   mxs_dma_init();
> diff --git a/arch/arm/imx-common/cpu.c b/arch/arm/imx-common/cpu.c
> index 0cd2538..5cac1a9 100644
> --- a/arch/arm/imx-common/cpu.c
> +++ b/arch/arm/imx-common/cpu.c
> @@ -171,9 +171,21 @@ u32 get_ahb_clk(void)
>   return get_periph_clk() / (ahb_podf + 1);
>  }
> 
> +static void set_anatop_bypass(void)
> +{
> + struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
> + u32 reg = readl(&anatop->reg_core);
> +
> + /* bypass VDDARM/VDDSOC */
> + reg = reg | (0x1F << 18) | 0x1F;
> + writel(reg, &anatop->reg_core);
> +}
> +
>  #if defined(CONFIG_VIDEO_IPUV3)
>  void arch_preboot_os(void)
>  {
> + set_anatop_bypass();
> +
>   /* disable video before launching O/S */
>   ipuv3_fb_shutdown();
>  }
> 
isn't the last change (enabling bypass) sufficient to fix the problem
or do you also need the 2 power_down before ?

Do you also get the kernel freeze without changing anything in
u-boot when you disable cpufreq in the kernel ?

Eric