From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752079AbdLDQCf (ORCPT ); Mon, 4 Dec 2017 11:02:35 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:33342 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752771AbdLDQC3 (ORCPT ); Mon, 4 Dec 2017 11:02:29 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Roman Kapl , Alex Deucher Subject: [PATCH 4.9 30/38] drm/radeon: fix atombios on big endian Date: Mon, 4 Dec 2017 17:00:10 +0100 Message-Id: <20171204160008.613847463@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171204160007.448534903@linuxfoundation.org> References: <20171204160007.448534903@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Roman Kapl commit 4f626a4ac8f57ddabf06d03870adab91e463217f upstream. The function for byteswapping the data send to/from atombios was buggy for num_bytes not divisible by four. The function must be aware of the fact that after byte-swapping the u32 units, valid bytes might end up after the num_bytes boundary. This patch was tested on kernel 3.12 and allowed us to sucesfully use DisplayPort on and Radeon SI card. Namely it fixed the link training and EDID readout. The function is patched both in radeon and amd drivers, since the functions and the fixes are identical. Signed-off-by: Roman Kapl Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c | 38 ++++++++++++--------------- drivers/gpu/drm/radeon/atombios_dp.c | 38 ++++++++++++--------------- 2 files changed, 36 insertions(+), 40 deletions(-) --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atombios.c @@ -1788,34 +1788,32 @@ void amdgpu_atombios_scratch_regs_restor WREG32(mmBIOS_SCRATCH_0 + i, adev->bios_scratch[i]); } -/* Atom needs data in little endian format - * so swap as appropriate when copying data to - * or from atom. Note that atom operates on - * dw units. +/* Atom needs data in little endian format so swap as appropriate when copying + * data to or from atom. Note that atom operates on dw units. + * + * Use to_le=true when sending data to atom and provide at least + * ALIGN(num_bytes,4) bytes in the dst buffer. + * + * Use to_le=false when receiving data from atom and provide ALIGN(num_bytes,4) + * byes in the src buffer. */ void amdgpu_atombios_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le) { #ifdef __BIG_ENDIAN - u8 src_tmp[20], dst_tmp[20]; /* used for byteswapping */ - u32 *dst32, *src32; + u32 src_tmp[5], dst_tmp[5]; int i; + u8 align_num_bytes = ALIGN(num_bytes, 4); - memcpy(src_tmp, src, num_bytes); - src32 = (u32 *)src_tmp; - dst32 = (u32 *)dst_tmp; if (to_le) { - for (i = 0; i < ((num_bytes + 3) / 4); i++) - dst32[i] = cpu_to_le32(src32[i]); - memcpy(dst, dst_tmp, num_bytes); + memcpy(src_tmp, src, num_bytes); + for (i = 0; i < align_num_bytes / 4; i++) + dst_tmp[i] = cpu_to_le32(src_tmp[i]); + memcpy(dst, dst_tmp, align_num_bytes); } else { - u8 dws = num_bytes & ~3; - for (i = 0; i < ((num_bytes + 3) / 4); i++) - dst32[i] = le32_to_cpu(src32[i]); - memcpy(dst, dst_tmp, dws); - if (num_bytes % 4) { - for (i = 0; i < (num_bytes % 4); i++) - dst[dws+i] = dst_tmp[dws+i]; - } + memcpy(src_tmp, src, align_num_bytes); + for (i = 0; i < align_num_bytes / 4; i++) + dst_tmp[i] = le32_to_cpu(src_tmp[i]); + memcpy(dst, dst_tmp, num_bytes); } #else memcpy(dst, src, num_bytes); --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -45,34 +45,32 @@ static char *pre_emph_names[] = { /***** radeon AUX functions *****/ -/* Atom needs data in little endian format - * so swap as appropriate when copying data to - * or from atom. Note that atom operates on - * dw units. +/* Atom needs data in little endian format so swap as appropriate when copying + * data to or from atom. Note that atom operates on dw units. + * + * Use to_le=true when sending data to atom and provide at least + * ALIGN(num_bytes,4) bytes in the dst buffer. + * + * Use to_le=false when receiving data from atom and provide ALIGN(num_bytes,4) + * byes in the src buffer. */ void radeon_atom_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le) { #ifdef __BIG_ENDIAN - u8 src_tmp[20], dst_tmp[20]; /* used for byteswapping */ - u32 *dst32, *src32; + u32 src_tmp[5], dst_tmp[5]; int i; + u8 align_num_bytes = ALIGN(num_bytes, 4); - memcpy(src_tmp, src, num_bytes); - src32 = (u32 *)src_tmp; - dst32 = (u32 *)dst_tmp; if (to_le) { - for (i = 0; i < ((num_bytes + 3) / 4); i++) - dst32[i] = cpu_to_le32(src32[i]); - memcpy(dst, dst_tmp, num_bytes); + memcpy(src_tmp, src, num_bytes); + for (i = 0; i < align_num_bytes / 4; i++) + dst_tmp[i] = cpu_to_le32(src_tmp[i]); + memcpy(dst, dst_tmp, align_num_bytes); } else { - u8 dws = num_bytes & ~3; - for (i = 0; i < ((num_bytes + 3) / 4); i++) - dst32[i] = le32_to_cpu(src32[i]); - memcpy(dst, dst_tmp, dws); - if (num_bytes % 4) { - for (i = 0; i < (num_bytes % 4); i++) - dst[dws+i] = dst_tmp[dws+i]; - } + memcpy(src_tmp, src, align_num_bytes); + for (i = 0; i < align_num_bytes / 4; i++) + dst_tmp[i] = le32_to_cpu(src_tmp[i]); + memcpy(dst, dst_tmp, num_bytes); } #else memcpy(dst, src, num_bytes);