From 34be8c9af7b8728465963740fc11136ae90dfc36 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Thu, 18 Jul 2013 11:13:53 -0400 Subject: [PATCH] drm/radeon: fix endian issues with DP handling (v3) The atom interpreter expects data in LE format, so swap the message buffer as apprioriate. v2: properly handle non-dw aligned byte counts. v3: properly handle remainder Signed-off-by: Alex Deucher Cc: Dong He Cc: stable@vger.kernel.org --- drivers/gpu/drm/radeon/atombios_dp.c | 43 +++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index 064023bed480..32501f6ec991 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -44,6 +44,41 @@ 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. + */ +static void radeon_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; + int i; + + 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); + } 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]; + } + } +#else + memcpy(dst, src, num_bytes); +#endif +} + union aux_channel_transaction { PROCESS_AUX_CHANNEL_TRANSACTION_PS_ALLOCATION v1; PROCESS_AUX_CHANNEL_TRANSACTION_PARAMETERS_V2 v2; @@ -65,10 +100,10 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan, base = (unsigned char *)(rdev->mode_info.atom_context->scratch + 1); - memcpy(base, send, send_bytes); + radeon_copy_swap(base, send, send_bytes, true); - args.v1.lpAuxRequest = 0 + 4; - args.v1.lpDataOut = 16 + 4; + args.v1.lpAuxRequest = cpu_to_le16((u16)(0 + 4)); + args.v1.lpDataOut = cpu_to_le16((u16)(16 + 4)); args.v1.ucDataOutLen = 0; args.v1.ucChannelID = chan->rec.i2c_id; args.v1.ucDelay = delay / 10; @@ -102,7 +137,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan *chan, recv_bytes = recv_size; if (recv && recv_size) - memcpy(recv, base + 16, recv_bytes); + radeon_copy_swap(recv, base + 16, recv_bytes, false); return recv_bytes; }