Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753790AbbFAUWL (ORCPT ); Mon, 1 Jun 2015 16:22:11 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:42787 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751540AbbFAUWD (ORCPT ); Mon, 1 Jun 2015 16:22:03 -0400 From: Stephen Boyd To: Russell King Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Lina Iyer Subject: [PATCH] ARM: Enter CPU in ARM state for cpu_resume Date: Mon, 1 Jun 2015 13:22:00 -0700 Message-Id: <1433190120-27798-1-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 2.3.0.rc1.33.g42e4583 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1885 Lines: 48 The standard boot protocol on ARM requires CPUs to be entered in the ARM state, unless they don't support the ARM instruction set (see Documentation/arm/Booting). On THUMB2 kernels, we assume the firmware can determine what state to enter the kernel in, but some firmwares don't honor the thumb bit. Make the cpu_resume symbol an ARM symbol, so that firmwares that honor the thumb bit will enter the kernel in ARM state and firmwares that don't honor the thumb bit will be able to enter the kernel in ARM state without more changes. This fixes a problem reported by Kevin Hilman where the ifc6410 fails to boot for THUMB2 kernels because the platform's firmware always enters the kernel in ARM mode from deep idle states. Reported-by: Kevin Hilman Suggested-by: Ard Biesheuvel Cc: Lina Iyer Signed-off-by: Stephen Boyd --- arch/arm/kernel/sleep.S | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S index 76bb3128e135..7c289ebb0b45 100644 --- a/arch/arm/kernel/sleep.S +++ b/arch/arm/kernel/sleep.S @@ -118,7 +118,12 @@ ENDPROC(cpu_resume_after_mmu) .text .align + .arm ENTRY(cpu_resume) + THUMB( badr r9, 1f ) @ Kernel is entered in ARM. + THUMB( bx r9 ) @ If this is a Thumb-2 kernel, + THUMB( .thumb ) @ switch to Thumb now. + THUMB(1: ) ARM_BE8(setend be) @ ensure we are in BE mode #ifdef CONFIG_ARM_VIRT_EXT bl __hyp_stub_install_secondary -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/