Tero Kristo <t-kristo@xxxxxx> writes:
> From: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
>
> Work around for Errata ID: i632 "LPDDR2 Corruption After OFF Mode
> Transition When CS1 Is Used On EMIF" which impacts OMAP443x silicon
> The issue occurs when EMIF_SDRAM_CONFIG is restored first before
> EMIF_SDRAM_CONFIG_2 is not yet restored, the register configuration
> is not set properly, we apply the required workaround allowing
> the restore sequence to work properly.
Please summarize the workaround here as well.
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> [t-kristo@xxxxxx: moved workaround from omap-sar.c to pm44xx.c]
> Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
> ---
> .../include/mach/ctrl_module_wkup_44xx.h | 2 +
> arch/arm/mach-omap2/pm44xx.c | 37 ++++++++++++++++++++
> 2 files changed, 39 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx.h b/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx.h
> index a0af9ba..b763a79 100644
> --- a/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx.h
> +++ b/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx.h
> @@ -28,6 +28,8 @@
> #define OMAP4_CTRL_MODULE_WKUP_IP_REVISION 0x0000
> #define OMAP4_CTRL_MODULE_WKUP_IP_HWINFO 0x0004
> #define OMAP4_CTRL_MODULE_WKUP_IP_SYSCONFIG 0x0010
> +#define OMAP4_CTRL_SECURE_EMIF1_SDRAM_CONFIG2_REG 0x0114
> +#define OMAP4_CTRL_SECURE_EMIF2_SDRAM_CONFIG2_REG 0x011c
> #define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_0 0x0460
> #define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_1 0x0464
> #define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_2 0x0468
> diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
> index 215b80e..dfaa254 100644
> --- a/arch/arm/mach-omap2/pm44xx.c
> +++ b/arch/arm/mach-omap2/pm44xx.c
> @@ -17,12 +17,18 @@
> #include <linux/err.h>
> #include <linux/slab.h>
> #include <asm/system_misc.h>
> +#include <linux/io.h>
> +
> +#include <mach/ctrl_module_wkup_44xx.h>
> +#include <mach/hardware.h>
>
> #include "common.h"
> #include "clockdomain.h"
> #include "powerdomain.h"
> #include "pm.h"
>
> +#define EMIF_SDRAM_CONFIG2_OFFSET 0xc
> +
> struct power_state {
> struct powerdomain *pwrdm;
> u32 next_state;
> @@ -215,6 +221,37 @@ static int __init omap4_pm_init(void)
>
> pr_err("Power Management for TI OMAP4.\n");
>
> + /*
> + * Work around for OMAP443x Errata i632: "LPDDR2 Corruption After OFF
> + * Mode Transition When CS1 Is Used On EMIF":
> + * Overwrite EMIF1/EMIF2
> + * SECURE_EMIF1_SDRAM_CONFIG2_REG
> + * SECURE_EMIF2_SDRAM_CONFIG2_REG
> + */
> + if (cpu_is_omap443x()) {
This should probably be done later in this function, after PM_ERRATUM
flags are setup, and then it should use a PM_ERRATUM flag instead of cpu_is*
> + void __iomem *secure_ctrl_mod;
> + void __iomem *emif1;
> + void __iomem *emif2;
> + u32 val;
> +
> + secure_ctrl_mod = ioremap(OMAP4_CTRL_MODULE_WKUP, SZ_4K);
> + emif1 = ioremap(OMAP44XX_EMIF1_BASE, SZ_1M);
> + emif2 = ioremap(OMAP44XX_EMIF2_BASE, SZ_1M);
> +
> + BUG_ON(!secure_ctrl_mod || !emif1 || !emif2);
Please avoid BUG_ON() and use proper error recovery. This is not a
condition where the entire kernel should panic.
> + val = __raw_readl(emif1 + EMIF_SDRAM_CONFIG2_OFFSET);
> + __raw_writel(val, secure_ctrl_mod +
> + OMAP4_CTRL_SECURE_EMIF1_SDRAM_CONFIG2_REG);
> + val = __raw_readl(emif2 + EMIF_SDRAM_CONFIG2_OFFSET);
> + __raw_writel(val, secure_ctrl_mod +
> + OMAP4_CTRL_SECURE_EMIF2_SDRAM_CONFIG2_REG);
> + wmb();
> + iounmap(secure_ctrl_mod);
> + iounmap(emif1);
> + iounmap(emif2);
> + }
>
> ret = pwrdm_for_each(pwrdms_setup, NULL);
> if (ret) {
> pr_err("Failed to setup powerdomains\n");
Kevin
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