On Tue, 2012-04-24 at 13:22 -0500, Jon Hunter wrote: > Hi Tero, > > On 04/20/2012 04:33 AM, Tero Kristo wrote: > > From: Santosh Shilimkar <[email protected]> > > > > 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. > > > > Signed-off-by: Santosh Shilimkar <[email protected]> > > [[email protected]: moved workaround from omap-sar.c to pm44xx.c] > > Signed-off-by: Tero Kristo <[email protected]> > > --- > > .../include/mach/ctrl_module_wkup_44xx.h | 2 + > > arch/arm/mach-omap2/pm44xx.c | 24 > > ++++++++++++++++++++ > > 2 files changed, 26 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 0472921..d4d18d9 100644 > > --- a/arch/arm/mach-omap2/pm44xx.c > > +++ b/arch/arm/mach-omap2/pm44xx.c > > @@ -17,6 +17,9 @@ > > #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 "common.h" > > #include "clockdomain.h" > > @@ -215,6 +218,27 @@ 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()) { > > + void __iomem *secure_ctrl_mod; > > + > > + secure_ctrl_mod = ioremap(OMAP4_CTRL_MODULE_WKUP, SZ_4K); > > + BUG_ON(!secure_ctrl_mod); > > + > > + __raw_writel(0x10, secure_ctrl_mod + > > + OMAP4_CTRL_SECURE_EMIF1_SDRAM_CONFIG2_REG); > > + __raw_writel(0x10, secure_ctrl_mod + > > + OMAP4_CTRL_SECURE_EMIF2_SDRAM_CONFIG2_REG); > > According to the erratum description the above registers are used to > restore the EMIFx_SDRAM_CONFIG2 registers. So although the value 0x10, > maybe the value being used for EMIFx_SDRAM_CONFIG2 registers, shouldn't > we read the EMIFx_SDRAM_CONFIG2 registers and store them in the above > registers?
This might be a good idea, however, this patch might be tagged as TEMP until the EMIF driver is in place, this fix should rather be located there. I'll take a look at this if I can change the implementation a bit. -Tero -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
