Tero Kristo <[email protected]> writes: > 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.
Please summarize the workaround here as well. > 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 | 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 -- 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
