drm/radeon/dpm/atom: restructure logic to work around a compiler bug

It seems gcc 4.8.1 generates bogus code for the old logic causing
part of the function to get skipped.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=66932
https://bugs.freedesktop.org/show_bug.cgi?id=66972
https://bugs.freedesktop.org/show_bug.cgi?id=66945

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/radeon/radeon_atombios.c b/drivers/gpu/drm/radeon/radeon_atombios.c
index a2e3241..2606ec6 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_atombios.c
+++ b/drivers/gpu/drm/radeon/radeon_atombios.c
@@ -3703,8 +3703,9 @@ int radeon_atom_init_mc_reg_table(struct radeon_device *rdev,
                                                           sizeof(ATOM_INIT_REG_INDEX_FORMAT)) - 1;
                                        if (num_entries > VBIOS_MC_REGISTER_ARRAY_SIZE)
                                                return -EINVAL;
-                                       while (!(reg_block->asRegIndexBuf[i].ucPreRegDataLength & ACCESS_PLACEHOLDER) &&
-                                             (i < num_entries)) {
+                                       while (i < num_entries) {
+                                               if (reg_block->asRegIndexBuf[i].ucPreRegDataLength & ACCESS_PLACEHOLDER)
+                                                       break;
                                                reg_table->mc_reg_address[i].s1 =
                                                        (u16)(le16_to_cpu(reg_block->asRegIndexBuf[i].usRegIndex));
                                                reg_table->mc_reg_address[i].pre_reg_data =