radeon_atombios_encoder_dpms_scratch_regs(struct drm_encoder *encoder, bool on)
{
	struct drm_device *dev = encoder->dev;
	struct radeon_device *rdev = dev->dev_private;
	struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
	uint32_t bios_2_scratch;

	if (rdev->family >= CHIP_R600)
		bios_2_scratch = RREG32(R600_BIOS_2_SCRATCH);
	else
		bios_2_scratch = RREG32(RADEON_BIOS_2_SCRATCH);

	if (radeon_encoder->devices & ATOM_DEVICE_TV1_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_TV1_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_TV1_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_CV_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_CV_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_CV_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_CRT1_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_CRT1_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_CRT1_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_CRT2_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_CRT2_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_CRT2_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_LCD1_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_LCD1_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_LCD1_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_DFP1_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_DFP1_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_DFP1_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_DFP2_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_DFP2_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_DFP2_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_DFP3_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_DFP3_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_DFP3_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_DFP4_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_DFP4_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_DFP4_DPMS_STATE;
	}
	if (radeon_encoder->devices & ATOM_DEVICE_DFP5_SUPPORT) {
		if (on)
			bios_2_scratch &= ~ATOM_S2_DFP5_DPMS_STATE;
		else
			bios_2_scratch |= ATOM_S2_DFP5_DPMS_STATE;
	}

	if (rdev->family >= CHIP_R600)
		WREG32(R600_BIOS_2_SCRATCH, bios_2_scratch);
	else
		WREG32(RADEON_BIOS_2_SCRATCH, bios_2_scratch);
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.