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drm/radeon: fix endian issues with DP handling (v3)

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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 <alexander.deucher@amd.com>
Cc: Dong He <hedonghust@gmail.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Alex Deucher 2013-07-18 11:13:53 -04:00
parent 3e3e53f86b
commit 34be8c9af7
1 changed files with 39 additions and 4 deletions
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43
drivers/gpu/drm/radeon/atombios_dp.c
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@ -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;
}