On Thu, May 17, 2012 at 5:45 AM, Kevin Hilman <khilman@xxxxxx> wrote:
> 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.
>
ok
>> 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*
>
ok
>> + 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.
>
Agree. WARN_ON() should suffice.
Regards
santosh
--
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
