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charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB2532.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3b2c1f05-ed8d-40ef-a995-08da9044f727 X-MS-Exchange-CrossTenant-originalarrivaltime: 06 Sep 2022 20:18:30.4937 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: dL9HsZkm7us4mTNclWgJ0GHA585hbNArnmBnpktvlrR58VT8yG85SU9Sr/hJCeL0eLyJPt5R/a6iM9e35f+wtA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR12MB4538 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "dri-devel@lists.freedesktop.org" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" [Public] Hi Daniel, I added the check because I saw that the refcount was always updated/read w= ith lock held elsewhere, and the pattern looked very similar to in the put = e.g. drm_crtc_vblank_reset. This patchset is outdated by now and I've sent = a fix to amd-gfx for the specific issue in amdgpu. However, I think the way drm_crtc_vblank_on/off functions increments the re= fcount without enabling the vblank is still a bit risky given how many unch= ecked calls to drm_vblank_get there is elsewhere. Maybe it's more appropria= te to simply add an WARN to drm_vblank_get when it's called with inmodeset = set? This way the WARN happens right at the problematic point, instead of f= ar into the future when the put is called. Yunxiang