From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Babic Date: Wed, 02 Apr 2014 17:26:13 +0200 Subject: [U-Boot] [PATCH v3 1/3] ARM: Add workaround for Cortex-A9 errata 794072 In-Reply-To: <1396446903-7967-2-git-send-email-nitin.garg@freescale.com> References: <1396446903-7967-1-git-send-email-nitin.garg@freescale.com> <1396446903-7967-2-git-send-email-nitin.garg@freescale.com> Message-ID: <533C2C15.6030400@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Nitin, On 02/04/2014 15:55, nitin.garg at freescale.com wrote: > From: Nitin Garg > > A short loop including a DMB instruction might cause a denial of > service on another processor which executes a CP15 broadcast operation. > Exists on r1, r2, r3, r4 revisions. > > Signed-off-by: Nitin Garg > Acked-by: Dirk Behme > --- > README | 1 + > arch/arm/cpu/armv7/start.S | 2 +- > 2 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/README b/README > index 7cb7c4f..a496c65 100644 > --- a/README > +++ b/README > @@ -566,6 +566,7 @@ The following options need to be configured: > CONFIG_ARM_ERRATA_742230 > CONFIG_ARM_ERRATA_743622 > CONFIG_ARM_ERRATA_751472 > + CONFIG_ARM_ERRATA_794072 > > If set, the workarounds for these ARM errata are applied early > during U-Boot startup. Note that these options force the > diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S > index ac1e55a..f3830c8 100644 > --- a/arch/arm/cpu/armv7/start.S > +++ b/arch/arm/cpu/armv7/start.S > @@ -205,7 +205,7 @@ ENTRY(cpu_init_cp15) > mcr p15, 0, r0, c1, c0, 0 @ write system control register > #endif > > -#ifdef CONFIG_ARM_ERRATA_742230 > +#if (defined(CONFIG_ARM_ERRATA_742230) || defined(CONFIG_ARM_ERRATA_794072)) > mrc p15, 0, r0, c15, c0, 1 @ read diagnostic register > orr r0, r0, #1 << 4 @ set bit #4 > mcr p15, 0, r0, c15, c0, 1 @ write diagnostic register > Apart having an additional errata number, which is the contribute of CONFIG_ARM_ERRATA_794072 ? We are already covered with CONFIG_ARM_ERRATA_742230 and the work-around for dmb is already implemented. Best regards, Stefano Babic -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de =====================================================================