From: Gregory CLEMENT Date: Sun, 23 Jun 2013 09:17:11 +0000 (+0100) Subject: ARM: 7773/1: PJ4B: Add support for errata 4742 X-Git-Tag: v3.10~19^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3e0a07f8c401bb43e0f964c5f1285b2cb2028645;p=pandora-kernel.git ARM: 7773/1: PJ4B: Add support for errata 4742 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 Acked-by: Nicolas Pitre Tested-by: Willy Tarreau Cc: Signed-off-by: Russell King --- Reading git-diff-tree failed