From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCHv2 15/19] ARM: OMAP4430: PM: workaround for DDR corruption on second CS Date: Thu, 17 May 2012 09:47:06 -0700 Message-ID: <87vcjuzred.fsf@ti.com> References: <1336990730-26892-1-git-send-email-t-kristo@ti.com> <1336990730-26892-16-git-send-email-t-kristo@ti.com> <87mx573boy.fsf@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from na3sys009aog103.obsmtp.com ([74.125.149.71]:51378 "EHLO na3sys009aog103.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758930Ab2EQQrJ convert rfc822-to-8bit (ORCPT ); Thu, 17 May 2012 12:47:09 -0400 Received: by pbbrp8 with SMTP id rp8so3874086pbb.33 for ; Thu, 17 May 2012 09:47:07 -0700 (PDT) In-Reply-To: (Santosh Shilimkar's message of "Thu, 17 May 2012 12:42:30 +0530") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Shilimkar, Santosh" Cc: Tero Kristo , linux-omap@vger.kernel.org, paul@pwsan.com, linux-arm-kernel@lists.infradead.org "Shilimkar, Santosh" writes: > On Thu, May 17, 2012 at 5:45 AM, Kevin Hilman wrote: >> Tero Kristo writes: >> >>> From: Santosh Shilimkar >>> >>> 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 >>> [t-kristo@ti.com: moved workaround from omap-sar.c to pm44xx.c] >>> Signed-off-by: Tero Kristo >>> --- >>> =C2=A0.../include/mach/ctrl_module_wkup_44xx.h =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 | =C2=A0 =C2=A02 + >>> =C2=A0arch/arm/mach-omap2/pm44xx.c =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 | =C2=A0 37 ++++++++++++++++= ++++ >>> =C2=A02 files changed, 39 insertions(+), 0 deletions(-) >>> >>> diff --git a/arch/arm/mach-omap2/include/mach/ctrl_module_wkup_44xx= =2Eh 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 @@ >>> =C2=A0#define OMAP4_CTRL_MODULE_WKUP_IP_REVISION =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 0x0000 >>> =C2=A0#define OMAP4_CTRL_MODULE_WKUP_IP_HWINFO =C2=A0 =C2=A0 =C2=A0= =C2=A0 =C2=A0 =C2=A0 0x0004 >>> =C2=A0#define OMAP4_CTRL_MODULE_WKUP_IP_SYSCONFIG =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A00x0010 >>> +#define OMAP4_CTRL_SECURE_EMIF1_SDRAM_CONFIG2_REG =C2=A0 =C2=A00x0= 114 >>> +#define OMAP4_CTRL_SECURE_EMIF2_SDRAM_CONFIG2_REG =C2=A0 =C2=A00x0= 11c >>> =C2=A0#define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_0 =C2=A00x0= 460 >>> =C2=A0#define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_1 =C2=A00x0= 464 >>> =C2=A0#define OMAP4_CTRL_MODULE_WKUP_CONF_DEBUG_SEL_TST_2 =C2=A00x0= 468 >>> diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm4= 4xx.c >>> index 215b80e..dfaa254 100644 >>> --- a/arch/arm/mach-omap2/pm44xx.c >>> +++ b/arch/arm/mach-omap2/pm44xx.c >>> @@ -17,12 +17,18 @@ >>> =C2=A0#include >>> =C2=A0#include >>> =C2=A0#include >>> +#include >>> + >>> +#include >>> +#include >>> >>> =C2=A0#include "common.h" >>> =C2=A0#include "clockdomain.h" >>> =C2=A0#include "powerdomain.h" >>> =C2=A0#include "pm.h" >>> >>> +#define EMIF_SDRAM_CONFIG2_OFFSET =C2=A0 =C2=A00xc >>> + >>> =C2=A0struct power_state { >>> =C2=A0 =C2=A0 =C2=A0 struct powerdomain *pwrdm; >>> =C2=A0 =C2=A0 =C2=A0 u32 next_state; >>> @@ -215,6 +221,37 @@ static int __init omap4_pm_init(void) >>> >>> =C2=A0 =C2=A0 =C2=A0 pr_err("Power Management for TI OMAP4.\n"); >>> >>> + =C2=A0 =C2=A0 /* >>> + =C2=A0 =C2=A0 =C2=A0* Work around for OMAP443x Errata i632: "LPDD= R2 Corruption After OFF >>> + =C2=A0 =C2=A0 =C2=A0* Mode Transition When CS1 Is Used On EMIF": >>> + =C2=A0 =C2=A0 =C2=A0* Overwrite EMIF1/EMIF2 >>> + =C2=A0 =C2=A0 =C2=A0* SECURE_EMIF1_SDRAM_CONFIG2_REG >>> + =C2=A0 =C2=A0 =C2=A0* SECURE_EMIF2_SDRAM_CONFIG2_REG >>> + =C2=A0 =C2=A0 =C2=A0*/ >>> + =C2=A0 =C2=A0 if (cpu_is_omap443x()) { >> >> This should probably be done later in this function, after PM_ERRATU= M >> flags are setup, and then it should use a PM_ERRATUM flag instead of= cpu_is* >> > ok > >>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 void __iomem *secure_ct= rl_mod; >>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 void __iomem *emif1; >>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 void __iomem *emif2; >>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 u32 val; >>> + >>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 secure_ctrl_mod =3D ior= emap(OMAP4_CTRL_MODULE_WKUP, SZ_4K); >>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 emif1 =3D ioremap(OMAP4= 4XX_EMIF1_BASE, SZ_1M); >>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 emif2 =3D ioremap(OMAP4= 4XX_EMIF2_BASE, SZ_1M); >>> + >>> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 BUG_ON(!secure_ctrl_mod= || !emif1 || !emif2); >> >> Please avoid BUG_ON() and use proper error recovery. =C2=A0This is n= ot a >> condition where the entire kernel should panic. >> > Agree. WARN_ON() should suffice. A WARN_ON() is ok (but noisy). Better is a pr_warn() with some proper error recovery. Kevin -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html