gpu: drm: dead code elimination

this set adds support for removal of gpu drm dead code.

patch3 is similar with patch 1:
`num` is a data of u8 type and ATOM_MAX_HW_I2C_READ == 255,

so there is a impossible condition '(num > 255) => (0-255 > 255)'.

Signed-off-by: Pan Zhang <zhangpan26@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/radeon/atombios_i2c.c b/drivers/gpu/drm/radeon/atombios_i2c.c
index a570ce40af191a0c14a16359f04174d9419e075f..ab4d21072191f949e6346bde18b298fedc9b9eb8 100644 (file)
--- a/drivers/gpu/drm/radeon/atombios_i2c.c
+++ b/drivers/gpu/drm/radeon/atombios_i2c.c
@@ -68,11 +68,6 @@ static int radeon_process_i2c_ch(struct radeon_i2c_chan *chan,
                        memcpy(&out, &buf[1], num);
                args.lpI2CDataOut = cpu_to_le16(out);
        } else {
-               if (num > ATOM_MAX_HW_I2C_READ) {
-                       DRM_ERROR("hw i2c: tried to read too many bytes (%d vs 255)\n", num);
-                       r = -EINVAL;
-                       goto done;
-               }
                args.ucRegIndex = 0;
                args.lpI2CDataOut = 0;
        }