From mboxrd@z Thu Jan 1 00:00:00 1970 From: w@1wt.eu (Willy Tarreau) Date: Sat, 22 Jun 2013 17:51:03 +0200 Subject: [PATCH v7] ARM PJ4B: Add support for errata 4742 In-Reply-To: <20130622154421.GA475@localhost> References: <1371828664-3681-1-git-send-email-gregory.clement@free-electrons.com> <1371828664-3681-2-git-send-email-gregory.clement@free-electrons.com> <20130622154421.GA475@localhost> Message-ID: <20130622155103.GA11542@1wt.eu> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sat, Jun 22, 2013 at 12:44:22PM -0300, Ezequiel Garcia wrote: > Hi Greg, > > On Fri, Jun 21, 2013 at 05:31:04PM +0200, Gregory CLEMENT wrote: > > This commit fixes the regression on Armada 370 (the kernal hang during > > boot) introduced by the commit: "ARM: 7691/1: mm: kill unused > > TLB_CAN_READ_FROM_L1_CACHE and use ALT_SMP instead". > > > > When coming out of either a Wait for Interrupt (WFI) or a Wait for > > Event (WFE) IDLE states, a specific timing sensitivity exists between > > the retiring WFI/WFE instructions and the newly issued subsequent > > instructions. This sensitivity can result in a CPU hang scenario. The > > workaround is to insert either a Data Synchronization Barrier (DSB) or > > Data Memory Barrier (DMB) command immediately after the WFI/WFE > > instruction. > > > > This commit was based on the work of Lior Amsalem, but heavily > > modified to apply the errata fix dynamically according to the > > processor type thanks to the suggestions of Russell King and Nicolas > > Pitre. > > > > Signed-off-by: Gregory CLEMENT > > Reviewed-by: Will Deacon > > Cc: > > This patch doesn't seem to apply on any 3.10-rcX; > maybe I'm doing something wrong, but could you double-check this? Interesting, I had the same issue and thought it was because of my tree, though visually I couldn't spot the issue. It probably was a space/tab issue only. Willy