Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757790Ab2HIKYZ (ORCPT ); Thu, 9 Aug 2012 06:24:25 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:41202 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757676Ab2HIKYX (ORCPT ); Thu, 9 Aug 2012 06:24:23 -0400 Date: Thu, 9 Aug 2012 11:24:14 +0100 From: Dave Martin To: Matt Sealey Cc: Sascha Hauer , Linux ARM Kernel Mailing List , Steev Klimaszewski , Linux Kernel Mailing List , Shawn Guo , Anton Vorontsov , Mark Brown , Sascha Hauer Subject: Re: [PATCH 1/2] ARM: build ssi-fiq.S in ARM mode to prevent CONFIG_THUMB2_KERNEL build breakage Message-ID: <20120809102414.GA17588@linaro.org> References: <1344379514-30076-1-git-send-email-matt@genesi-usa.com> <1344379514-30076-2-git-send-email-matt@genesi-usa.com> <20120808065502.GI1451@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3908 Lines: 158 On Wed, Aug 08, 2012 at 12:32:39PM -0500, Matt Sealey wrote: [...] > I'm going to do a trapse through and find where Russell nacked Dave's > thumb-aware > rewrite.. would you mind if you have any of these boards seeing if it > really DOES There was no NAK because I didn't get as far as posting the patch, mostly because of the doubt about whether this code is ever relevant on Thumb2-capable hardware. If somebody with some old imx hardware that definitely relies on this wants to pick it up and test it, it might still be useful. I don't know whether I still have the original patch, but I think the only think I did was to swap the roles of r13 and r12. In the original code r12 is only used as a base register, which is permissible usage for r13 in Thumb-2. Those two registers appear private to the fiq handler, so I don't think the change will break anything, but I'd be more confident is somebody is able to test it. Cheers ---Dave diff --git a/arch/arm/plat-mxc/ssi-fiq.S b/arch/arm/plat-mxc/ssi-fiq.S index 8397a2d..3589afb 100644 --- a/arch/arm/plat-mxc/ssi-fiq.S +++ b/arch/arm/plat-mxc/ssi-fiq.S @@ -35,19 +35,19 @@ .global imx_ssi_fiq_tx_buffer imx_ssi_fiq_start: - ldr r12, imx_ssi_fiq_base + ldr r13, imx_ssi_fiq_base /* TX */ ldr r11, imx_ssi_fiq_tx_buffer /* shall we send? */ - ldr r13, [r12, #SSI_SIER] - tst r13, #SSI_SIER_TFE0_EN + ldr r12, [r13, #SSI_SIER] + tst r12, #SSI_SIER_TFE0_EN beq 1f /* TX FIFO empty? */ - ldr r13, [r12, #SSI_SISR] - tst r13, #SSI_SISR_TFE0 + ldr r12, [r13, #SSI_SISR] + tst r12, #SSI_SISR_TFE0 beq 1f mov r10, #0x10000 @@ -56,34 +56,34 @@ imx_ssi_fiq_start: add r11, r11, r10 - ldrh r13, [r11] - strh r13, [r12, #SSI_STX0] + ldrh r12, [r11] + strh r12, [r13, #SSI_STX0] - ldrh r13, [r11, #2] - strh r13, [r12, #SSI_STX0] + ldrh r12, [r11, #2] + strh r12, [r13, #SSI_STX0] - ldrh r13, [r11, #4] - strh r13, [r12, #SSI_STX0] + ldrh r12, [r11, #4] + strh r12, [r13, #SSI_STX0] - ldrh r13, [r11, #6] - strh r13, [r12, #SSI_STX0] + ldrh r12, [r11, #6] + strh r12, [r13, #SSI_STX0] add r10, #8 - lsr r13, r8, #16 /* r13: buffer size */ - cmp r10, r13 - lslgt r8, r13, #16 + lsr r12, r8, #16 /* r12: buffer size */ + cmp r10, r12 + lslgt r8, r12, #16 addle r8, #8 1: /* RX */ /* shall we receive? */ - ldr r13, [r12, #SSI_SIER] - tst r13, #SSI_SIER_RFF0_EN + ldr r12, [r13, #SSI_SIER] + tst r12, #SSI_SIER_RFF0_EN beq 1f /* RX FIFO full? */ - ldr r13, [r12, #SSI_SISR] - tst r13, #SSI_SISR_RFF0 + ldr r12, [r13, #SSI_SISR] + tst r12, #SSI_SISR_RFF0 beq 1f ldr r11, imx_ssi_fiq_rx_buffer @@ -94,31 +94,31 @@ imx_ssi_fiq_start: add r11, r11, r10 - ldr r13, [r12, #SSI_SACNT] - tst r13, #SSI_SACNT_AC97EN + ldr r12, [r13, #SSI_SACNT] + tst r12, #SSI_SACNT_AC97EN - ldr r13, [r12, #SSI_SRX0] - strh r13, [r11] + ldr r12, [r13, #SSI_SRX0] + strh r12, [r11] - ldr r13, [r12, #SSI_SRX0] - strh r13, [r11, #2] + ldr r12, [r13, #SSI_SRX0] + strh r12, [r11, #2] /* dummy read to skip slot 12 */ - ldrne r13, [r12, #SSI_SRX0] + ldrne r12, [r13, #SSI_SRX0] - ldr r13, [r12, #SSI_SRX0] - strh r13, [r11, #4] + ldr r12, [r13, #SSI_SRX0] + strh r12, [r11, #4] - ldr r13, [r12, #SSI_SRX0] - strh r13, [r11, #6] + ldr r12, [r13, #SSI_SRX0] + strh r12, [r11, #6] /* dummy read to skip slot 12 */ - ldrne r13, [r12, #SSI_SRX0] + ldrne r12, [r13, #SSI_SRX0] add r10, #8 - lsr r13, r9, #16 /* r13: buffer size */ - cmp r10, r13 - lslgt r9, r13, #16 + lsr r12, r9, #16 /* r12: buffer size */ + cmp r10, r12 + lslgt r9, r12, #16 addle r9, #8 1: -- 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/