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Commit 04ee39ba authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm: Only take crtc lock in get_gamma ioctl 



We don't call into drivers at all here, this is enough. Also, we can
reduce the critical section a bit to simplify the code.
crtc->gamma_size is set up once at driver load and then invariant, so
also doesn't need any protection.

Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170403083304.9083-8-daniel.vetter@ffwll.ch
parent eb8eb02e

drivers/gpu/drm/drm_color_mgmt.c

+6 −10
Original line number Diff line number Diff line
@@ -295,19 +295,15 @@ int drm_mode_gamma_get_ioctl(struct drm_device *dev, 
	if (!drm_core_check_feature(dev, DRIVER_MODESET))

		return -EINVAL;



	drm_modeset_lock_all(dev);

	crtc = drm_crtc_find(dev, crtc_lut->crtc_id);

	if (!crtc) {

		ret = -ENOENT;

		goto out;

	}

	if (!crtc)

		return -ENOENT;



	/* memcpy into gamma store */

	if (crtc_lut->gamma_size != crtc->gamma_size) {

		ret = -EINVAL;

		goto out;

	}

	if (crtc_lut->gamma_size != crtc->gamma_size)

		return -EINVAL;



	drm_modeset_lock(&crtc->mutex, NULL);

	size = crtc_lut->gamma_size * (sizeof(uint16_t));

	r_base = crtc->gamma_store;

	if (copy_to_user((void __user *)(unsigned long)crtc_lut->red, r_base, size)) {
@@ -327,6 +323,6 @@ int drm_mode_gamma_get_ioctl(struct drm_device *dev, 
		goto out;

	}

out:

	drm_modeset_unlock_all(dev);

	drm_modeset_unlock(&crtc->mutex);

	return ret;

}