From mboxrd@z Thu Jan 1 00:00:00 1970 From: Imre Deak Subject: Re: [PATCH] backlight: Avoid double fbcon backlight handling Date: Thu, 30 Jun 2016 15:47:51 +0300 Message-ID: <1467290871.5576.15.camel@intel.com> References: <1467286256-8870-1-git-send-email-chris@chris-wilson.co.uk> Reply-To: imre.deak@intel.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <1467286256-8870-1-git-send-email-chris@chris-wilson.co.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Chris Wilson , intel-gfx@lists.freedesktop.org Cc: Milo Kim , Krzysztof Kozlowski , David Airlie , nouveau@lists.freedesktop.org, Jon Nettleton , Nicolas Ferre , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Thierry Reding , Paul Mackerras , Laurent Pinchart , Daniel Vetter , Lee Jones , Daniel Drake , Jens Frederich , linux-acpi@vger.kernel.org, Bruno =?ISO-8859-1?Q?Pr=E9mont?= , Tomi Valkeinen , Ben Skeggs , Zhang Rui , Jean-Christophe Plagniol-Villard , Michael Hennerich , Jiri Kosina List-Id: linux-acpi@vger.kernel.org T24gdG8sIDIwMTYtMDYtMzAgYXQgMTI6MzAgKzAxMDAsIENocmlzIFdpbHNvbiB3cm90ZToKPiBC YWNrbGlnaHRzIGNvbnRyb2xsZWQgYnkgaTkxNS5rbyBhbmQgb25seSBhc3NvY2lhdGVkIHdpdGgg aXRzCj4gY29ubmVjdG9ycwo+IGFuZCBhbHNvIG9ubHkgYXNzb2NpYXRlZCB3aXRoIHRoZSBpbnRl bF9kcm1mYiBmYmNvbiwgY29udHJvbGxlZCBieQo+IGk5MTUua28uIEluIHRoaXMgc2l0dWF0aW9u LCB3ZSBhbHJlYWR5IGhhbmRsZSBhZGp1c3RpbmcgdGhlIGJhY2tsaWdodAo+IHdoZW4gdGhlIGZi Y29uIGlzIGJsYW5rZWQvdW5ibGFua2VkIGFuZCBkbyBub3QgcmVxdWlyZSBiYWNrbGlnaHQKPiB0 cnlpbmcKPiB0byBkbyB0aGUgc2FtZS4KPiAKPiBBdHRlbXB0aW5nIHRvIHJlZ2lzdGVyIHdpdGgg dGhlIGZiZGV2IGFzIGEgY2xpZW50IGNhdXNlcyBsb2NrZGVwIHRvCj4gd2Fybgo+IGFib3V0IGEg ZGVwZW5kZW5jeSBjeWNsZToKPiAKPiBbwqDCoMKgMTguOTgzNzYzXSA9PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KPiBbwqDCoMKgMTguOTgzNzYz XSBbIElORk86IHBvc3NpYmxlIGNpcmN1bGFyIGxvY2tpbmcgZGVwZW5kZW5jeSBkZXRlY3RlZAo+ IF0KPiBbwqDCoMKgMTguOTgzNzY2XSA0LjcuMC1yYzUrICM1MjQgVGFpbnRlZDogR8KgwqDCoMKg wqDCoMKgwqDCoMKgwqBPCj4gW8KgwqDCoDE4Ljk4Mzc2N10gLS0tLS0tLS0tLS0tLS0tLS0tLS0t LS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tCj4gLQo+IFvCoMKgwqAxOC45ODM3Njdd IGt3b3JrZXIvdTg6MC82IGlzIHRyeWluZyB0byBhY3F1aXJlIGxvY2s6Cj4gW8KgwqDCoDE4Ljk4 Mzc3N13CoMKgKCZkZXYtPm1vZGVfY29uZmlnLm11dGV4KXsrLisuKy59LCBhdDoKPiBbPGZmZmZm ZmZmODE1YWZkZTA+XSBkcm1fbW9kZXNldF9sb2NrX2FsbCsweDQwLzB4MTIwCj4gW8KgwqDCoDE4 Ljk4Mzc3N10KPiDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqBidXQgdGFzayBpcyBhbHJl YWR5IGhvbGRpbmcgbG9jazoKPiBbwqDCoMKgMTguOTgzNzgyXcKgwqAoKGZiX25vdGlmaWVyX2xp c3QpLnJ3c2VtKXsrKysrLit9LCBhdDoKPiBbPGZmZmZmZmZmODEwYWMxOTU+XSBfX2Jsb2NraW5n X25vdGlmaWVyX2NhbGxfY2hhaW4rMHgzNS8weDcwCj4gW8KgwqDCoDE4Ljk4Mzc4M10KPiDCoMKg wqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqB3aGljaCBsb2NrIGFscmVhZHkgZGVwZW5kcyBvbiB0 aGUgbmV3IGxvY2suCj4gCj4gW8KgwqDCoDE4Ljk4Mzc4M10KPiDCoMKgwqDCoMKgwqDCoMKgwqDC oMKgwqDCoMKgwqB0aGUgZXhpc3RpbmcgZGVwZW5kZW5jeSBjaGFpbiAoaW4gcmV2ZXJzZSBvcmRl cikgaXM6Cj4gW8KgwqDCoDE4Ljk4Mzc4NV0KPiDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKg wqAtPiAjMSAoKGZiX25vdGlmaWVyX2xpc3QpLnJ3c2VtKXsrKysrLit9Ogo+IFvCoMKgwqAxOC45 ODM3ODldwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTBkZjYxMT5dIGxvY2tfYWNxdWlyZSsw eGIxLzB4MjAwCj4gW8KgwqDCoDE4Ljk4Mzc5Ml3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgx OWE1NWI0Pl0gZG93bl93cml0ZSsweDQ0LzB4ODAKPiBbwqDCoMKgMTguOTgzNzk1XcKgwqDCoMKg wqDCoMKgwqBbPGZmZmZmZmZmODEwYWJmOTE+XQo+IGJsb2NraW5nX25vdGlmaWVyX2NoYWluX3Jl Z2lzdGVyKzB4MjEvMHhiMAo+IFvCoMKgwqAxOC45ODM3OThdwqDCoMKgwqDCoMKgwqDCoFs8ZmZm ZmZmZmY4MTRjNzQ0OD5dCj4gZmJfcmVnaXN0ZXJfY2xpZW50KzB4MTgvMHgyMAo+IFvCoMKgwqAx OC45ODM4MDBdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTRjNmM4Nj5dCj4gYmFja2xpZ2h0 X2RldmljZV9yZWdpc3RlcisweDEzNi8weDI2MAo+IFvCoMKgwqAxOC45ODM4NTJdwqDCoMKgwqDC oMKgwqDCoFs8ZmZmZmZmZmZhMDEyN2ViMj5dCj4gaW50ZWxfYmFja2xpZ2h0X2RldmljZV9yZWdp c3RlcisweGEyLzB4MTYwIFtpOTE1XQo+IFvCoMKgwqAxOC45ODM4OTJdwqDCoMKgwqDCoMKgwqDC oFs8ZmZmZmZmZmZhMDBmNDZiZT5dCj4gaW50ZWxfY29ubmVjdG9yX3JlZ2lzdGVyKzB4ZS8weDEw IFtpOTE1XQo+IFvCoMKgwqAxOC45ODM5MzJdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmZhMDEx MmJmYj5dCj4gaW50ZWxfZHBfY29ubmVjdG9yX3JlZ2lzdGVyKzB4MWIvMHg4MCBbaTkxNV0KPiBb wqDCoMKgMTguOTgzOTM2XcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZmZmZmODE1OWRmZWE+XQo+IGRy bV9jb25uZWN0b3JfcmVnaXN0ZXIrMHg0YS8weDgwCj4gW8KgwqDCoDE4Ljk4MzkzOF3CoMKgwqDC oMKgwqDCoMKgWzxmZmZmZmZmZjgxNTlmZTQ0Pl0KPiBkcm1fY29ubmVjdG9yX3JlZ2lzdGVyX2Fs bCsweDY0LzB4ZjAKPiBbwqDCoMKgMTguOTgzOTQwXcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZmZmZm ODE1YTJhNjQ+XQo+IGRybV9tb2Rlc2V0X3JlZ2lzdGVyX2FsbCsweDE3NC8weDFjMAo+IFvCoMKg wqAxOC45ODM5NDJdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTU5OWI3Mj5dIGRybV9kZXZf cmVnaXN0ZXIrMHhjMi8weGQwCj4gW8KgwqDCoDE4Ljk4Mzk3Nl3CoMKgwqDCoMKgwqDCoMKgWzxm ZmZmZmZmZmEwMDYyMWQ3Pl0KPiBpOTE1X2RyaXZlcl9sb2FkKzB4MTU0Ny8weDIyMDAgW2k5MTVd Cj4gW8KgwqDCoDE4Ljk4NDAxMF3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZmEwMDZkODBmPl0g aTkxNV9wY2lfcHJvYmUrMHg0Zi8weDcwCj4gW2k5MTVdCj4gW8KgwqDCoDE4Ljk4NDAxNF3CoMKg wqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxNGEyMTM1Pl0gbG9jYWxfcGNpX3Byb2JlKzB4NDUvMHhh MAo+IFvCoMKgwqAxOC45ODQwMTVdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTRhMzQ5Yj5d Cj4gcGNpX2RldmljZV9wcm9iZSsweGRiLzB4MTMwCj4gW8KgwqDCoDE4Ljk4NDAxOF3CoMKgwqDC oMKgwqDCoMKgWzxmZmZmZmZmZjgxNWMwN2UzPl0KPiBkcml2ZXJfcHJvYmVfZGV2aWNlKzB4MjIz LzB4NDQwCj4gW8KgwqDCoDE4Ljk4NDAyMF3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxNWMw YWQ1Pl0gX19kcml2ZXJfYXR0YWNoKzB4ZDUvMHgxMDAKPiBbwqDCoMKgMTguOTg0MDIyXcKgwqDC oMKgwqDCoMKgwqBbPGZmZmZmZmZmODE1YmUzODY+XSBidXNfZm9yX2VhY2hfZGV2KzB4NjYvMHhh MAo+IFvCoMKgwqAxOC45ODQwMjNdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTVjMDAyZT5d IGRyaXZlcl9hdHRhY2grMHgxZS8weDIwCj4gW8KgwqDCoDE4Ljk4NDAyNV3CoMKgwqDCoMKgwqDC oMKgWzxmZmZmZmZmZjgxNWJmOWJlPl0gYnVzX2FkZF9kcml2ZXIrMHgxZWUvMHgyODAKPiBbwqDC oMKgMTguOTg0MDI4XcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZmZmZmODE1YzE4MTA+XSBkcml2ZXJf cmVnaXN0ZXIrMHg2MC8weGUwCj4gW8KgwqDCoDE4Ljk4NDAzMF3CoMKgwqDCoMKgwqDCoMKgWzxm ZmZmZmZmZjgxNGExYTEwPl0KPiBfX3BjaV9yZWdpc3Rlcl9kcml2ZXIrMHg2MC8weDcwCj4gW8Kg wqDCoDE4Ljk4NDA2M13CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZmEwMWE5MDViPl0gaTkxNV9p bml0KzB4NWIvMHg2MiBbaTkxNV0KPiBbwqDCoMKgMTguOTg0MDY3XcKgwqDCoMKgwqDCoMKgwqBb PGZmZmZmZmZmODEwMDA0MmQ+XSBkb19vbmVfaW5pdGNhbGwrMHgzZC8weDE1MAo+IFvCoMKgwqAx OC45ODQwNzBdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTFhOTM1Yj5dIGRvX2luaXRfbW9k dWxlKzB4NWYvMHgxZDkKPiBbwqDCoMKgMTguOTg0MDczXcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZm ZmZmODExMjQ0MTY+XSBsb2FkX21vZHVsZSsweDIwZTYvMHgyN2UwCj4gW8KgwqDCoDE4Ljk4NDA3 NV3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxMTI0ZDYzPl0KPiBTWVNDX2Zpbml0X21vZHVs ZSsweGMzLzB4ZjAKPiBbwqDCoMKgMTguOTg0MDc2XcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZmZmZm ODExMjRkYWU+XSBTeVNfZmluaXRfbW9kdWxlKzB4ZS8weDEwCj4gW8KgwqDCoDE4Ljk4NDA3OV3C oMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxOWE4M2E5Pl0KPiBlbnRyeV9TWVNDQUxMXzY0X2Zh c3RwYXRoKzB4MWMvMHhhYwo+IFvCoMKgwqAxOC45ODQwODFdCj4gwqDCoMKgwqDCoMKgwqDCoMKg wqDCoMKgwqDCoMKgLT4gIzAgKCZkZXYtPm1vZGVfY29uZmlnLm11dGV4KXsrLisuKy59Ogo+IFvC oMKgwqAxOC45ODQwODNdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTBkZjBhYz5dCj4gX19s b2NrX2FjcXVpcmUrMHgxMGZjLzB4MTI2MAo+IFvCoMKgwqAxOC45ODQwODVdwqDCoMKgwqDCoMKg wqDCoFs8ZmZmZmZmZmY4MTBkZjYxMT5dIGxvY2tfYWNxdWlyZSsweGIxLzB4MjAwCj4gW8KgwqDC oDE4Ljk4NDA4OF3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxOWEzMDk3Pl0KPiBtdXRleF9s b2NrX25lc3RlZCsweDY3LzB4M2MwCj4gW8KgwqDCoDE4Ljk4NDA5MF3CoMKgwqDCoMKgwqDCoMKg WzxmZmZmZmZmZjgxNWFmZGUwPl0KPiBkcm1fbW9kZXNldF9sb2NrX2FsbCsweDQwLzB4MTIwCj4g W8KgwqDCoDE4Ljk4NDA5M13CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxNThmNzliPl0KPiBk cm1fZmJfaGVscGVyX3Jlc3RvcmVfZmJkZXZfbW9kZV91bmxvY2tlZCsweDJiLzB4ODAKPiBbwqDC oMKgMTguOTg0MDk1XcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZmZmZmODE1OGY4MWQ+XQo+IGRybV9m Yl9oZWxwZXJfc2V0X3BhcisweDJkLzB4NTAKPiBbwqDCoMKgMTguOTg0MTM0XcKgwqDCoMKgwqDC oMKgwqBbPGZmZmZmZmZmYTAxMDVmN2E+XQo+IGludGVsX2ZiZGV2X3NldF9wYXIrMHgxYS8weDYw IFtpOTE1XQo+IFvCoMKgwqAxOC45ODQxMzZdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTRj MTNjNj5dIGZiY29uX2luaXQrMHg1ODYvMHg2MTAKPiBbwqDCoMKgMTguOTg0MTM5XcKgwqDCoMKg wqDCoMKgwqBbPGZmZmZmZmZmODE1NGQxNmE+XSB2aXN1YWxfaW5pdCsweGNhLzB4MTMwCj4gW8Kg wqDCoDE4Ljk4NDE0MV3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxNTRlNjExPl0KPiBkb19i aW5kX2Nvbl9kcml2ZXIrMHgxYzEvMHgzYTAKPiBbwqDCoMKgMTguOTg0MTQzXcKgwqDCoMKgwqDC oMKgwqBbPGZmZmZmZmZmODE1NGVhZjY+XQo+IGRvX3Rha2Vfb3Zlcl9jb25zb2xlKzB4MTE2LzB4 MTgwCj4gW8KgwqDCoDE4Ljk4NDE0NV3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxNGJkM2E3 Pl0KPiBkb19mYmNvbl90YWtlb3ZlcisweDU3LzB4YjAKPiBbwqDCoMKgMTguOTg0MTQ3XcKgwqDC oMKgwqDCoMKgwqBbPGZmZmZmZmZmODE0YzFlNDg+XQo+IGZiY29uX2V2ZW50X25vdGlmeSsweDY1 OC8weDc1MAo+IFvCoMKgwqAxOC45ODQxNTBdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTBh YmNhZT5dCj4gbm90aWZpZXJfY2FsbF9jaGFpbisweDNlLzB4YjAKPiBbwqDCoMKgMTguOTg0MTUy XcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZmZmZmODEwYWMxYWQ+XQo+IF9fYmxvY2tpbmdfbm90aWZp ZXJfY2FsbF9jaGFpbisweDRkLzB4NzAKPiBbwqDCoMKgMTguOTg0MTU0XcKgwqDCoMKgwqDCoMKg wqBbPGZmZmZmZmZmODEwYWMxZTY+XQo+IGJsb2NraW5nX25vdGlmaWVyX2NhbGxfY2hhaW4rMHgx Ni8weDIwCj4gW8KgwqDCoDE4Ljk4NDE1Nl3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxNGM3 NDhiPl0KPiBmYl9ub3RpZmllcl9jYWxsX2NoYWluKzB4MWIvMHgyMAo+IFvCoMKgwqAxOC45ODQx NThdwqDCoMKgwqDCoMKgwqDCoFs8ZmZmZmZmZmY4MTRjODZiMT5dCj4gcmVnaXN0ZXJfZnJhbWVi dWZmZXIrMHgyNTEvMHgzMzAKPiBbwqDCoMKgMTguOTg0MTYwXcKgwqDCoMKgwqDCoMKgwqBbPGZm ZmZmZmZmODE1OGZhOWY+XQo+IGRybV9mYl9oZWxwZXJfaW5pdGlhbF9jb25maWcrMHgyNWYvMHgz ZjAKPiBbwqDCoMKgMTguOTg0MTk5XcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZmZmZmYTAxMDZiNDg+ XQo+IGludGVsX2ZiZGV2X2luaXRpYWxfY29uZmlnKzB4MTgvMHgzMCBbaTkxNV0KPiBbwqDCoMKg MTguOTg0MjAxXcKgwqDCoMKgwqDCoMKgwqBbPGZmZmZmZmZmODEwYWRmZDg+XQo+IGFzeW5jX3J1 bl9lbnRyeV9mbisweDQ4LzB4MTUwCj4gW8KgwqDCoDE4Ljk4NDIwM13CoMKgwqDCoMKgwqDCoMKg WzxmZmZmZmZmZjgxMGEzOTQ3Pl0KPiBwcm9jZXNzX29uZV93b3JrKzB4MWU3LzB4NzUwCj4gW8Kg wqDCoDE4Ljk4NDIwNV3CoMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxMGEzZWZiPl0gd29ya2Vy X3RocmVhZCsweDRiLzB4NGYwCj4gW8KgwqDCoDE4Ljk4NDIwN13CoMKgwqDCoMKgwqDCoMKgWzxm ZmZmZmZmZjgxMGFhZDRmPl0ga3RocmVhZCsweGVmLzB4MTEwCj4gW8KgwqDCoDE4Ljk4NDIwOF3C oMKgwqDCoMKgwqDCoMKgWzxmZmZmZmZmZjgxOWE4NWVmPl0gcmV0X2Zyb21fZm9yaysweDFmLzB4 NDAKPiBbwqDCoMKgMTguOTg0MjA5XQo+IMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoG90 aGVyIGluZm8gdGhhdCBtaWdodCBoZWxwIHVzIGRlYnVnIHRoaXM6Cj4gCj4gW8KgwqDCoDE4Ljk4 NDIxMF3CoMKgUG9zc2libGUgdW5zYWZlIGxvY2tpbmcgc2NlbmFyaW86Cj4gCj4gW8KgwqDCoDE4 Ljk4NDIxMF3CoMKgwqDCoMKgwqDCoMKgQ1BVMMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDC oMKgwqDCoMKgwqBDUFUxCj4gW8KgwqDCoDE4Ljk4NDIxMV3CoMKgwqDCoMKgwqDCoMKgLS0tLcKg wqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqAtLS0tCj4gW8KgwqDCoDE4Ljk4 NDIxMl3CoMKgwqBsb2NrKChmYl9ub3RpZmllcl9saXN0KS5yd3NlbSk7Cj4gW8KgwqDCoDE4Ljk4 NDIxM13CoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKg wqDCoMKgwqDCoMKgbG9jaygmZGV2LQo+ID5tb2RlX2NvbmZpZy5tdXRleCk7Cj4gW8KgwqDCoDE4 Ljk4NDIxNV3CoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDC oMKgwqDCoMKgwqDCoMKgbG9jaygoZmJfbm90aWZpZXJfbGlzdCkKPiAucndzZW0pOwo+IFvCoMKg wqAxOC45ODQyMTZdwqDCoMKgbG9jaygmZGV2LT5tb2RlX2NvbmZpZy5tdXRleCk7Cj4gW8KgwqDC oDE4Ljk4NDIxNl0KPiDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoMKgwqDCoCoqKiBERUFETE9D SyAqKioKPiAKPiBbwqDCoMKgMTguOTg0MjE3XSA2IGxvY2tzIGhlbGQgYnkga3dvcmtlci91ODow LzY6Cj4gW8KgwqDCoDE4Ljk4NDIyMF3CoMKgIzA6wqDCoCgiZXZlbnRzX3VuYm91bmQiKXsuKy4r Lit9LCBhdDoKPiBbPGZmZmZmZmZmODEwYTM4Yzk+XSBwcm9jZXNzX29uZV93b3JrKzB4MTY5LzB4 NzUwCj4gW8KgwqDCoDE4Ljk4NDIyM13CoMKgIzE6wqDCoCgoJmVudHJ5LT53b3JrKSl7Ky4rLisu fSwgYXQ6Cj4gWzxmZmZmZmZmZjgxMGEzOGM5Pl0gcHJvY2Vzc19vbmVfd29yaysweDE2OS8weDc1 MAo+IFvCoMKgwqAxOC45ODQyMjddwqDCoCMyOsKgwqAocmVnaXN0cmF0aW9uX2xvY2speysuKy4r Ln0sIGF0Ogo+IFs8ZmZmZmZmZmY4MTRjODQ4Nz5dIHJlZ2lzdGVyX2ZyYW1lYnVmZmVyKzB4Mjcv MHgzMzAKPiBbwqDCoMKgMTguOTg0MjMxXcKgwqAjMzrCoMKgKGNvbnNvbGVfbG9jayl7Ky4rLisu fSwgYXQ6IFs8ZmZmZmZmZmY4MTRjODZjZT5dCj4gcmVnaXN0ZXJfZnJhbWVidWZmZXIrMHgyNmUv MHgzMzAKPiBbwqDCoMKgMTguOTg0MjM0XcKgwqAjNDrCoMKgKCZmYl9pbmZvLT5sb2NrKXsrLisu Ky59LCBhdDoKPiBbPGZmZmZmZmZmODE0Yzc4ZGQ+XSBsb2NrX2ZiX2luZm8rMHgxZC8weDQwCj4g W8KgwqDCoDE4Ljk4NDIzOF3CoMKgIzU6wqDCoCgoZmJfbm90aWZpZXJfbGlzdCkucndzZW0peysr KysuK30sIGF0Ogo+IFs8ZmZmZmZmZmY4MTBhYzE5NT5dIF9fYmxvY2tpbmdfbm90aWZpZXJfY2Fs bF9jaGFpbisweDM1LzB4NzAKPiBbwqDCoMKgMTguOTg0MjM4XQo+IMKgwqDCoMKgwqDCoMKgwqDC oMKgwqDCoMKgwqDCoHN0YWNrIGJhY2t0cmFjZToKPiBbwqDCoMKgMTguOTg0MjQxXSBDUFU6IDIg UElEOiA2IENvbW06IGt3b3JrZXIvdTg6MCBUYWludGVkOgo+IEfCoMKgwqDCoMKgwqDCoMKgwqDC oMKgT8KgwqDCoMKgNC43LjAtcmM1KyAjNTI0Cj4gW8KgwqDCoDE4Ljk4NDI0Ml0gSGFyZHdhcmUg bmFtZTogSW50ZWwgQ29ycC4gQnJveHRvbiBQL05PVEVCT09LLCBCSU9TCj4gQVBMS1JWUEEuWDY0 LjAxMzguQjMzLjE2MDYyNTA4NDIgMDYvMjUvMjAxNgo+IFvCoMKgwqAxOC45ODQyNDRdIFdvcmtx dWV1ZTogZXZlbnRzX3VuYm91bmQgYXN5bmNfcnVuX2VudHJ5X2ZuCj4gW8KgwqDCoDE4Ljk4NDI0 OF3CoMKgMDAwMDAwMDAwMDAwMDAwMCBmZmZmODgwMDc1ODU3N2YwIGZmZmZmZmZmODE0NTA3YTUK PiBmZmZmZmZmZjgyOGI5OTAwCj4gW8KgwqDCoDE4Ljk4NDI1MF3CoMKgZmZmZmZmZmY4MjhiOTkw MCBmZmZmODgwMDc1ODU3ODMwIGZmZmZmZmZmODEwZGM2ZmEKPiBmZmZmODgwMDc1ODU3ODgwCj4g W8KgwqDCoDE4Ljk4NDI1Ml3CoMKgZmZmZjg4MDA3NTg0ZDY4OCAwMDAwMDAwMDAwMDAwMDA1IDAw MDAwMDAwMDAwMDAwMDYKPiBmZmZmODgwMDc1ODRkNmIwCj4gW8KgwqDCoDE4Ljk4NDI1M10gQ2Fs bCBUcmFjZToKPiBbwqDCoMKgMTguOTg0MjU3XcKgwqBbPGZmZmZmZmZmODE0NTA3YTU+XSBkdW1w X3N0YWNrKzB4NjcvMHg5Mgo+IFvCoMKgwqAxOC45ODQyNTldwqDCoFs8ZmZmZmZmZmY4MTBkYzZm YT5dIHByaW50X2NpcmN1bGFyX2J1ZysweDFhYS8weDIwMAo+IFvCoMKgwqAxOC45ODQyNjFdwqDC oFs8ZmZmZmZmZmY4MTBkZjBhYz5dIF9fbG9ja19hY3F1aXJlKzB4MTBmYy8weDEyNjAKPiBbwqDC oMKgMTguOTg0MjY0XcKgwqBbPGZmZmZmZmZmODEwZGY2MTE+XSBsb2NrX2FjcXVpcmUrMHhiMS8w eDIwMAo+IFvCoMKgwqAxOC45ODQyNjZdwqDCoFs8ZmZmZmZmZmY4MTVhZmRlMD5dID8KPiBkcm1f bW9kZXNldF9sb2NrX2FsbCsweDQwLzB4MTIwCj4gW8KgwqDCoDE4Ljk4NDI2N13CoMKgWzxmZmZm ZmZmZjgxNWFmZGUwPl0gPwo+IGRybV9tb2Rlc2V0X2xvY2tfYWxsKzB4NDAvMHgxMjAKPiBbwqDC oMKgMTguOTg0MjY5XcKgwqBbPGZmZmZmZmZmODE5YTMwOTc+XSBtdXRleF9sb2NrX25lc3RlZCsw eDY3LzB4M2MwCj4gW8KgwqDCoDE4Ljk4NDI3MV3CoMKgWzxmZmZmZmZmZjgxNWFmZGUwPl0gPwo+ IGRybV9tb2Rlc2V0X2xvY2tfYWxsKzB4NDAvMHgxMjAKPiBbwqDCoMKgMTguOTg0MjczXcKgwqBb PGZmZmZmZmZmODEwZmE4NWY+XSA/Cj4gcmN1X3JlYWRfbG9ja19zY2hlZF9oZWxkKzB4N2YvMHg5 MAo+IFvCoMKgwqAxOC45ODQyNzZdwqDCoFs8ZmZmZmZmZmY4MTIwODIxOD5dID8KPiBrbWVtX2Nh Y2hlX2FsbG9jX3RyYWNlKzB4MjQ4LzB4MmIwCj4gW8KgwqDCoDE4Ljk4NDI3N13CoMKgWzxmZmZm ZmZmZjgxNWFmZGM1Pl0gPwo+IGRybV9tb2Rlc2V0X2xvY2tfYWxsKzB4MjUvMHgxMjAKPiBbwqDC oMKgMTguOTg0Mjc5XcKgwqBbPGZmZmZmZmZmODE1YWZkZTA+XSBkcm1fbW9kZXNldF9sb2NrX2Fs bCsweDQwLzB4MTIwCj4gW8KgwqDCoDE4Ljk4NDI4MV3CoMKgWzxmZmZmZmZmZjgxNThmNzliPl0K PiBkcm1fZmJfaGVscGVyX3Jlc3RvcmVfZmJkZXZfbW9kZV91bmxvY2tlZCsweDJiLzB4ODAKPiBb wqDCoMKgMTguOTg0MjgzXcKgwqBbPGZmZmZmZmZmODE1OGY4MWQ+XSBkcm1fZmJfaGVscGVyX3Nl dF9wYXIrMHgyZC8weDUwCj4gW8KgwqDCoDE4Ljk4NDMyMl3CoMKgWzxmZmZmZmZmZmEwMTA1Zjdh Pl0gaW50ZWxfZmJkZXZfc2V0X3BhcisweDFhLzB4NjAKPiBbaTkxNV0KPiBbwqDCoMKgMTguOTg0 MzI0XcKgwqBbPGZmZmZmZmZmODE0YzEzYzY+XSBmYmNvbl9pbml0KzB4NTg2LzB4NjEwCj4gW8Kg wqDCoDE4Ljk4NDMyNl3CoMKgWzxmZmZmZmZmZjgxNTRkMTZhPl0gdmlzdWFsX2luaXQrMHhjYS8w eDEzMAo+IFvCoMKgwqAxOC45ODQzMjhdwqDCoFs8ZmZmZmZmZmY4MTU0ZTYxMT5dIGRvX2JpbmRf Y29uX2RyaXZlcisweDFjMS8weDNhMAo+IFvCoMKgwqAxOC45ODQzMzBdwqDCoFs8ZmZmZmZmZmY4 MTU0ZWFmNj5dIGRvX3Rha2Vfb3Zlcl9jb25zb2xlKzB4MTE2LzB4MTgwCj4gW8KgwqDCoDE4Ljk4 NDMzMl3CoMKgWzxmZmZmZmZmZjgxNGJkM2E3Pl0gZG9fZmJjb25fdGFrZW92ZXIrMHg1Ny8weGIw Cj4gW8KgwqDCoDE4Ljk4NDMzNF3CoMKgWzxmZmZmZmZmZjgxNGMxZTQ4Pl0gZmJjb25fZXZlbnRf bm90aWZ5KzB4NjU4LzB4NzUwCj4gW8KgwqDCoDE4Ljk4NDMzNl3CoMKgWzxmZmZmZmZmZjgxMGFi Y2FlPl0gbm90aWZpZXJfY2FsbF9jaGFpbisweDNlLzB4YjAKPiBbwqDCoMKgMTguOTg0MzM4XcKg wqBbPGZmZmZmZmZmODEwYWMxYWQ+XQo+IF9fYmxvY2tpbmdfbm90aWZpZXJfY2FsbF9jaGFpbisw eDRkLzB4NzAKPiBbwqDCoMKgMTguOTg0MzQwXcKgwqBbPGZmZmZmZmZmODEwYWMxZTY+XQo+IGJs b2NraW5nX25vdGlmaWVyX2NhbGxfY2hhaW4rMHgxNi8weDIwCj4gW8KgwqDCoDE4Ljk4NDM0Ml3C oMKgWzxmZmZmZmZmZjgxNGM3NDhiPl0gZmJfbm90aWZpZXJfY2FsbF9jaGFpbisweDFiLzB4MjAK PiBbwqDCoMKgMTguOTg0MzQ0XcKgwqBbPGZmZmZmZmZmODE0Yzg2YjE+XSByZWdpc3Rlcl9mcmFt ZWJ1ZmZlcisweDI1MS8weDMzMAo+IFvCoMKgwqAxOC45ODQzNDddwqDCoFs8ZmZmZmZmZmY4MTVi N2U4ZD5dID8KPiB2Z2Ffc3dpdGNoZXJvb19jbGllbnRfZmJfc2V0KzB4NWQvMHg3MAo+IFvCoMKg wqAxOC45ODQzNDldwqDCoFs8ZmZmZmZmZmY4MTU4ZmE5Zj5dCj4gZHJtX2ZiX2hlbHBlcl9pbml0 aWFsX2NvbmZpZysweDI1Zi8weDNmMAo+IFvCoMKgwqAxOC45ODQzODhdwqDCoFs8ZmZmZmZmZmZh MDEwNmI0OD5dCj4gaW50ZWxfZmJkZXZfaW5pdGlhbF9jb25maWcrMHgxOC8weDMwIFtpOTE1XQo+ IFvCoMKgwqAxOC45ODQzODldwqDCoFs8ZmZmZmZmZmY4MTBhZGZkOD5dIGFzeW5jX3J1bl9lbnRy eV9mbisweDQ4LzB4MTUwCj4gW8KgwqDCoDE4Ljk4NDM5MV3CoMKgWzxmZmZmZmZmZjgxMGEzOTQ3 Pl0gcHJvY2Vzc19vbmVfd29yaysweDFlNy8weDc1MAo+IFvCoMKgwqAxOC45ODQzOTJdwqDCoFs8 ZmZmZmZmZmY4MTBhMzhjOT5dID8gcHJvY2Vzc19vbmVfd29yaysweDE2OS8weDc1MAo+IFvCoMKg wqAxOC45ODQzOTRdwqDCoFs8ZmZmZmZmZmY4MTBhM2VmYj5dIHdvcmtlcl90aHJlYWQrMHg0Yi8w eDRmMAo+IFvCoMKgwqAxOC45ODQzOTZdwqDCoFs8ZmZmZmZmZmY4MTBhM2ViMD5dID8gcHJvY2Vz c19vbmVfd29yaysweDc1MC8weDc1MAo+IFvCoMKgwqAxOC45ODQzOThdwqDCoFs8ZmZmZmZmZmY4 MTBhYWQ0Zj5dIGt0aHJlYWQrMHhlZi8weDExMAo+IFvCoMKgwqAxOC45ODQ0MDFdwqDCoFs8ZmZm ZmZmZmY4MTlhODVlZj5dIHJldF9mcm9tX2ZvcmsrMHgxZi8weDQwCj4gW8KgwqDCoDE4Ljk4NDQw Ml3CoMKgWzxmZmZmZmZmZjgxMGFhYzYwPl0gPyBrdGhyZWFkX3N0b3ArMHgyZTAvMHgyZTAKPiAK PiBSZXBvcnRlZC1ieTogSW1yZSBEZWFrIDxpbXJlLmRlYWtAaW50ZWwuY29tPgoKVGhhbmtzLCBp dCBnZXRzIHJpZCBvZiB0aGUgcHJvYmxlbToKVGVzdGVkLWJ5OiBJbXJlIERlYWsgPGltcmUuZGVh a0BpbnRlbC5jb20+CgotLUltcmUKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX18KSW50ZWwtZ2Z4IG1haWxpbmcgbGlzdApJbnRlbC1nZnhAbGlzdHMuZnJlZWRl c2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8v aW50ZWwtZ2Z4Cg== From mboxrd@z Thu Jan 1 00:00:00 1970 From: Imre Deak Date: Thu, 30 Jun 2016 12:47:51 +0000 Subject: Re: [PATCH] backlight: Avoid double fbcon backlight handling Message-Id: <1467290871.5576.15.camel@intel.com> List-Id: References: <1467286256-8870-1-git-send-email-chris@chris-wilson.co.uk> In-Reply-To: <1467286256-8870-1-git-send-email-chris@chris-wilson.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Chris Wilson , intel-gfx@lists.freedesktop.org Cc: Milo Kim , Krzysztof Kozlowski , David Airlie , nouveau@lists.freedesktop.org, Jon Nettleton , Nicolas Ferre , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Thierry Reding , Paul Mackerras , Laurent Pinchart , Daniel Vetter , Lee Jones , Daniel Drake , Jens Frederich , linux-acpi@vger.kernel.org, Bruno =?ISO-8859-1?Q?Pr=E9mont?= , Tomi Valkeinen , Ben Skeggs , Zhang Rui , Jean-Christophe Plagniol-Villard , Michael Hennerich , Jiri Kosina On to, 2016-06-30 at 12:30 +0100, Chris Wilson wrote: > Backlights controlled by i915.ko and only associated with its > connectors > and also only associated with the intel_drmfb fbcon, controlled by > i915.ko. In this situation, we already handle adjusting the backlight > when the fbcon is blanked/unblanked and do not require backlight > trying > to do the same. > > Attempting to register with the fbdev as a client causes lockdep to > warn > about a dependency cycle: > > [   18.983763] =========================== > [   18.983763] [ INFO: possible circular locking dependency detected > ] > [   18.983766] 4.7.0-rc5+ #524 Tainted: G           O > [   18.983767] ------------------------------------------------------ > - > [   18.983767] kworker/u8:0/6 is trying to acquire lock: > [   18.983777]  (&dev->mode_config.mutex){+.+.+.}, at: > [] drm_modeset_lock_all+0x40/0x120 > [   18.983777] >                but task is already holding lock: > [   18.983782]  ((fb_notifier_list).rwsem){++++.+}, at: > [] __blocking_notifier_call_chain+0x35/0x70 > [   18.983783] >                which lock already depends on the new lock. > > [   18.983783] >                the existing dependency chain (in reverse order) is: > [   18.983785] >                -> #1 ((fb_notifier_list).rwsem){++++.+}: > [   18.983789]        [] lock_acquire+0xb1/0x200 > [   18.983792]        [] down_write+0x44/0x80 > [   18.983795]        [] > blocking_notifier_chain_register+0x21/0xb0 > [   18.983798]        [] > fb_register_client+0x18/0x20 > [   18.983800]        [] > backlight_device_register+0x136/0x260 > [   18.983852]        [] > intel_backlight_device_register+0xa2/0x160 [i915] > [   18.983892]        [] > intel_connector_register+0xe/0x10 [i915] > [   18.983932]        [] > intel_dp_connector_register+0x1b/0x80 [i915] > [   18.983936]        [] > drm_connector_register+0x4a/0x80 > [   18.983938]        [] > drm_connector_register_all+0x64/0xf0 > [   18.983940]        [] > drm_modeset_register_all+0x174/0x1c0 > [   18.983942]        [] drm_dev_register+0xc2/0xd0 > [   18.983976]        [] > i915_driver_load+0x1547/0x2200 [i915] > [   18.984010]        [] i915_pci_probe+0x4f/0x70 > [i915] > [   18.984014]        [] local_pci_probe+0x45/0xa0 > [   18.984015]        [] > pci_device_probe+0xdb/0x130 > [   18.984018]        [] > driver_probe_device+0x223/0x440 > [   18.984020]        [] __driver_attach+0xd5/0x100 > [   18.984022]        [] bus_for_each_dev+0x66/0xa0 > [   18.984023]        [] driver_attach+0x1e/0x20 > [   18.984025]        [] bus_add_driver+0x1ee/0x280 > [   18.984028]        [] driver_register+0x60/0xe0 > [   18.984030]        [] > __pci_register_driver+0x60/0x70 > [   18.984063]        [] i915_init+0x5b/0x62 [i915] > [   18.984067]        [] do_one_initcall+0x3d/0x150 > [   18.984070]        [] do_init_module+0x5f/0x1d9 > [   18.984073]        [] load_module+0x20e6/0x27e0 > [   18.984075]        [] > SYSC_finit_module+0xc3/0xf0 > [   18.984076]        [] SyS_finit_module+0xe/0x10 > [   18.984079]        [] > entry_SYSCALL_64_fastpath+0x1c/0xac > [   18.984081] >                -> #0 (&dev->mode_config.mutex){+.+.+.}: > [   18.984083]        [] > __lock_acquire+0x10fc/0x1260 > [   18.984085]        [] lock_acquire+0xb1/0x200 > [   18.984088]        [] > mutex_lock_nested+0x67/0x3c0 > [   18.984090]        [] > drm_modeset_lock_all+0x40/0x120 > [   18.984093]        [] > drm_fb_helper_restore_fbdev_mode_unlocked+0x2b/0x80 > [   18.984095]        [] > drm_fb_helper_set_par+0x2d/0x50 > [   18.984134]        [] > intel_fbdev_set_par+0x1a/0x60 [i915] > [   18.984136]        [] fbcon_init+0x586/0x610 > [   18.984139]        [] visual_init+0xca/0x130 > [   18.984141]        [] > do_bind_con_driver+0x1c1/0x3a0 > [   18.984143]        [] > do_take_over_console+0x116/0x180 > [   18.984145]        [] > do_fbcon_takeover+0x57/0xb0 > [   18.984147]        [] > fbcon_event_notify+0x658/0x750 > [   18.984150]        [] > notifier_call_chain+0x3e/0xb0 > [   18.984152]        [] > __blocking_notifier_call_chain+0x4d/0x70 > [   18.984154]        [] > blocking_notifier_call_chain+0x16/0x20 > [   18.984156]        [] > fb_notifier_call_chain+0x1b/0x20 > [   18.984158]        [] > register_framebuffer+0x251/0x330 > [   18.984160]        [] > drm_fb_helper_initial_config+0x25f/0x3f0 > [   18.984199]        [] > intel_fbdev_initial_config+0x18/0x30 [i915] > [   18.984201]        [] > async_run_entry_fn+0x48/0x150 > [   18.984203]        [] > process_one_work+0x1e7/0x750 > [   18.984205]        [] worker_thread+0x4b/0x4f0 > [   18.984207]        [] kthread+0xef/0x110 > [   18.984208]        [] ret_from_fork+0x1f/0x40 > [   18.984209] >                other info that might help us debug this: > > [   18.984210]  Possible unsafe locking scenario: > > [   18.984210]        CPU0                    CPU1 > [   18.984211]        ----                    ---- > [   18.984212]   lock((fb_notifier_list).rwsem); > [   18.984213]                                lock(&dev- > >mode_config.mutex); > [   18.984215]                                lock((fb_notifier_list) > .rwsem); > [   18.984216]   lock(&dev->mode_config.mutex); > [   18.984216] >                 *** DEADLOCK *** > > [   18.984217] 6 locks held by kworker/u8:0/6: > [   18.984220]  #0:  ("events_unbound"){.+.+.+}, at: > [] process_one_work+0x169/0x750 > [   18.984223]  #1:  ((&entry->work)){+.+.+.}, at: > [] process_one_work+0x169/0x750 > [   18.984227]  #2:  (registration_lock){+.+.+.}, at: > [] register_framebuffer+0x27/0x330 > [   18.984231]  #3:  (console_lock){+.+.+.}, at: [] > register_framebuffer+0x26e/0x330 > [   18.984234]  #4:  (&fb_info->lock){+.+.+.}, at: > [] lock_fb_info+0x1d/0x40 > [   18.984238]  #5:  ((fb_notifier_list).rwsem){++++.+}, at: > [] __blocking_notifier_call_chain+0x35/0x70 > [   18.984238] >                stack backtrace: > [   18.984241] CPU: 2 PID: 6 Comm: kworker/u8:0 Tainted: > G           O    4.7.0-rc5+ #524 > [   18.984242] Hardware name: Intel Corp. Broxton P/NOTEBOOK, BIOS > APLKRVPA.X64.0138.B33.1606250842 06/25/2016 > [   18.984244] Workqueue: events_unbound async_run_entry_fn > [   18.984248]  0000000000000000 ffff8800758577f0 ffffffff814507a5 > ffffffff828b9900 > [   18.984250]  ffffffff828b9900 ffff880075857830 ffffffff810dc6fa > ffff880075857880 > [   18.984252]  ffff88007584d688 0000000000000005 0000000000000006 > ffff88007584d6b0 > [   18.984253] Call Trace: > [   18.984257]  [] dump_stack+0x67/0x92 > [   18.984259]  [] print_circular_bug+0x1aa/0x200 > [   18.984261]  [] __lock_acquire+0x10fc/0x1260 > [   18.984264]  [] lock_acquire+0xb1/0x200 > [   18.984266]  [] ? > drm_modeset_lock_all+0x40/0x120 > [   18.984267]  [] ? > drm_modeset_lock_all+0x40/0x120 > [   18.984269]  [] mutex_lock_nested+0x67/0x3c0 > [   18.984271]  [] ? > drm_modeset_lock_all+0x40/0x120 > [   18.984273]  [] ? > rcu_read_lock_sched_held+0x7f/0x90 > [   18.984276]  [] ? > kmem_cache_alloc_trace+0x248/0x2b0 > [   18.984277]  [] ? > drm_modeset_lock_all+0x25/0x120 > [   18.984279]  [] drm_modeset_lock_all+0x40/0x120 > [   18.984281]  [] > drm_fb_helper_restore_fbdev_mode_unlocked+0x2b/0x80 > [   18.984283]  [] drm_fb_helper_set_par+0x2d/0x50 > [   18.984322]  [] intel_fbdev_set_par+0x1a/0x60 > [i915] > [   18.984324]  [] fbcon_init+0x586/0x610 > [   18.984326]  [] visual_init+0xca/0x130 > [   18.984328]  [] do_bind_con_driver+0x1c1/0x3a0 > [   18.984330]  [] do_take_over_console+0x116/0x180 > [   18.984332]  [] do_fbcon_takeover+0x57/0xb0 > [   18.984334]  [] fbcon_event_notify+0x658/0x750 > [   18.984336]  [] notifier_call_chain+0x3e/0xb0 > [   18.984338]  [] > __blocking_notifier_call_chain+0x4d/0x70 > [   18.984340]  [] > blocking_notifier_call_chain+0x16/0x20 > [   18.984342]  [] fb_notifier_call_chain+0x1b/0x20 > [   18.984344]  [] register_framebuffer+0x251/0x330 > [   18.984347]  [] ? > vga_switcheroo_client_fb_set+0x5d/0x70 > [   18.984349]  [] > drm_fb_helper_initial_config+0x25f/0x3f0 > [   18.984388]  [] > intel_fbdev_initial_config+0x18/0x30 [i915] > [   18.984389]  [] async_run_entry_fn+0x48/0x150 > [   18.984391]  [] process_one_work+0x1e7/0x750 > [   18.984392]  [] ? process_one_work+0x169/0x750 > [   18.984394]  [] worker_thread+0x4b/0x4f0 > [   18.984396]  [] ? process_one_work+0x750/0x750 > [   18.984398]  [] kthread+0xef/0x110 > [   18.984401]  [] ret_from_fork+0x1f/0x40 > [   18.984402]  [] ? kthread_stop+0x2e0/0x2e0 > > Reported-by: Imre Deak Thanks, it gets rid of the problem: Tested-by: Imre Deak --Imre From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com ([192.55.52.120]:14118 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751424AbcF3MvG (ORCPT ); Thu, 30 Jun 2016 08:51:06 -0400 Message-ID: <1467290871.5576.15.camel@intel.com> Subject: Re: [PATCH] backlight: Avoid double fbcon backlight handling From: Imre Deak Reply-To: imre.deak@intel.com To: Chris Wilson , intel-gfx@lists.freedesktop.org Cc: Zhang Rui , Alex Deucher , Christian =?ISO-8859-1?Q?K=F6nig?= , David Airlie , Patrik Jakobsson , Daniel Vetter , Jani Nikula , Ben Skeggs , Tomi Valkeinen , Laurent Pinchart , Bruno =?ISO-8859-1?Q?Pr=E9mont?= , Jiri Kosina , Thomas Petazzoni , Noralf =?ISO-8859-1?Q?Tr=F8nnes?= , Jens Frederich , Daniel Drake , Jon Nettleton , Jingoo Han , Lee Jones , Jean-Christophe Plagniol-Villard , Michael Hennerich , Milo Kim , Thierry Reding , Nicolas Ferre , Paul Mackerras , Kukjin Kim , Krzysztof Kozlowski , Antonino Daplas , linux-acpi@vger.kernel.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-renesas-soc@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-omap@vger.kernel.org Date: Thu, 30 Jun 2016 15:47:51 +0300 In-Reply-To: <1467286256-8870-1-git-send-email-chris@chris-wilson.co.uk> References: <1467286256-8870-1-git-send-email-chris@chris-wilson.co.uk> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: On to, 2016-06-30 at 12:30 +0100, Chris Wilson wrote: > Backlights controlled by i915.ko and only associated with its > connectors > and also only associated with the intel_drmfb fbcon, controlled by > i915.ko. In this situation, we already handle adjusting the backlight > when the fbcon is blanked/unblanked and do not require backlight > trying > to do the same. > > Attempting to register with the fbdev as a client causes lockdep to > warn > about a dependency cycle: > > [   18.983763] ====================================================== > [   18.983763] [ INFO: possible circular locking dependency detected > ] > [   18.983766] 4.7.0-rc5+ #524 Tainted: G           O > [   18.983767] ------------------------------------------------------ > - > [   18.983767] kworker/u8:0/6 is trying to acquire lock: > [   18.983777]  (&dev->mode_config.mutex){+.+.+.}, at: > [] drm_modeset_lock_all+0x40/0x120 > [   18.983777] >                but task is already holding lock: > [   18.983782]  ((fb_notifier_list).rwsem){++++.+}, at: > [] __blocking_notifier_call_chain+0x35/0x70 > [   18.983783] >                which lock already depends on the new lock. > > [   18.983783] >                the existing dependency chain (in reverse order) is: > [   18.983785] >                -> #1 ((fb_notifier_list).rwsem){++++.+}: > [   18.983789]        [] lock_acquire+0xb1/0x200 > [   18.983792]        [] down_write+0x44/0x80 > [   18.983795]        [] > blocking_notifier_chain_register+0x21/0xb0 > [   18.983798]        [] > fb_register_client+0x18/0x20 > [   18.983800]        [] > backlight_device_register+0x136/0x260 > [   18.983852]        [] > intel_backlight_device_register+0xa2/0x160 [i915] > [   18.983892]        [] > intel_connector_register+0xe/0x10 [i915] > [   18.983932]        [] > intel_dp_connector_register+0x1b/0x80 [i915] > [   18.983936]        [] > drm_connector_register+0x4a/0x80 > [   18.983938]        [] > drm_connector_register_all+0x64/0xf0 > [   18.983940]        [] > drm_modeset_register_all+0x174/0x1c0 > [   18.983942]        [] drm_dev_register+0xc2/0xd0 > [   18.983976]        [] > i915_driver_load+0x1547/0x2200 [i915] > [   18.984010]        [] i915_pci_probe+0x4f/0x70 > [i915] > [   18.984014]        [] local_pci_probe+0x45/0xa0 > [   18.984015]        [] > pci_device_probe+0xdb/0x130 > [   18.984018]        [] > driver_probe_device+0x223/0x440 > [   18.984020]        [] __driver_attach+0xd5/0x100 > [   18.984022]        [] bus_for_each_dev+0x66/0xa0 > [   18.984023]        [] driver_attach+0x1e/0x20 > [   18.984025]        [] bus_add_driver+0x1ee/0x280 > [   18.984028]        [] driver_register+0x60/0xe0 > [   18.984030]        [] > __pci_register_driver+0x60/0x70 > [   18.984063]        [] i915_init+0x5b/0x62 [i915] > [   18.984067]        [] do_one_initcall+0x3d/0x150 > [   18.984070]        [] do_init_module+0x5f/0x1d9 > [   18.984073]        [] load_module+0x20e6/0x27e0 > [   18.984075]        [] > SYSC_finit_module+0xc3/0xf0 > [   18.984076]        [] SyS_finit_module+0xe/0x10 > [   18.984079]        [] > entry_SYSCALL_64_fastpath+0x1c/0xac > [   18.984081] >                -> #0 (&dev->mode_config.mutex){+.+.+.}: > [   18.984083]        [] > __lock_acquire+0x10fc/0x1260 > [   18.984085]        [] lock_acquire+0xb1/0x200 > [   18.984088]        [] > mutex_lock_nested+0x67/0x3c0 > [   18.984090]        [] > drm_modeset_lock_all+0x40/0x120 > [   18.984093]        [] > drm_fb_helper_restore_fbdev_mode_unlocked+0x2b/0x80 > [   18.984095]        [] > drm_fb_helper_set_par+0x2d/0x50 > [   18.984134]        [] > intel_fbdev_set_par+0x1a/0x60 [i915] > [   18.984136]        [] fbcon_init+0x586/0x610 > [   18.984139]        [] visual_init+0xca/0x130 > [   18.984141]        [] > do_bind_con_driver+0x1c1/0x3a0 > [   18.984143]        [] > do_take_over_console+0x116/0x180 > [   18.984145]        [] > do_fbcon_takeover+0x57/0xb0 > [   18.984147]        [] > fbcon_event_notify+0x658/0x750 > [   18.984150]        [] > notifier_call_chain+0x3e/0xb0 > [   18.984152]        [] > __blocking_notifier_call_chain+0x4d/0x70 > [   18.984154]        [] > blocking_notifier_call_chain+0x16/0x20 > [   18.984156]        [] > fb_notifier_call_chain+0x1b/0x20 > [   18.984158]        [] > register_framebuffer+0x251/0x330 > [   18.984160]        [] > drm_fb_helper_initial_config+0x25f/0x3f0 > [   18.984199]        [] > intel_fbdev_initial_config+0x18/0x30 [i915] > [   18.984201]        [] > async_run_entry_fn+0x48/0x150 > [   18.984203]        [] > process_one_work+0x1e7/0x750 > [   18.984205]        [] worker_thread+0x4b/0x4f0 > [   18.984207]        [] kthread+0xef/0x110 > [   18.984208]        [] ret_from_fork+0x1f/0x40 > [   18.984209] >                other info that might help us debug this: > > [   18.984210]  Possible unsafe locking scenario: > > [   18.984210]        CPU0                    CPU1 > [   18.984211]        ----                    ---- > [   18.984212]   lock((fb_notifier_list).rwsem); > [   18.984213]                                lock(&dev- > >mode_config.mutex); > [   18.984215]                                lock((fb_notifier_list) > .rwsem); > [   18.984216]   lock(&dev->mode_config.mutex); > [   18.984216] >                 *** DEADLOCK *** > > [   18.984217] 6 locks held by kworker/u8:0/6: > [   18.984220]  #0:  ("events_unbound"){.+.+.+}, at: > [] process_one_work+0x169/0x750 > [   18.984223]  #1:  ((&entry->work)){+.+.+.}, at: > [] process_one_work+0x169/0x750 > [   18.984227]  #2:  (registration_lock){+.+.+.}, at: > [] register_framebuffer+0x27/0x330 > [   18.984231]  #3:  (console_lock){+.+.+.}, at: [] > register_framebuffer+0x26e/0x330 > [   18.984234]  #4:  (&fb_info->lock){+.+.+.}, at: > [] lock_fb_info+0x1d/0x40 > [   18.984238]  #5:  ((fb_notifier_list).rwsem){++++.+}, at: > [] __blocking_notifier_call_chain+0x35/0x70 > [   18.984238] >                stack backtrace: > [   18.984241] CPU: 2 PID: 6 Comm: kworker/u8:0 Tainted: > G           O    4.7.0-rc5+ #524 > [   18.984242] Hardware name: Intel Corp. Broxton P/NOTEBOOK, BIOS > APLKRVPA.X64.0138.B33.1606250842 06/25/2016 > [   18.984244] Workqueue: events_unbound async_run_entry_fn > [   18.984248]  0000000000000000 ffff8800758577f0 ffffffff814507a5 > ffffffff828b9900 > [   18.984250]  ffffffff828b9900 ffff880075857830 ffffffff810dc6fa > ffff880075857880 > [   18.984252]  ffff88007584d688 0000000000000005 0000000000000006 > ffff88007584d6b0 > [   18.984253] Call Trace: > [   18.984257]  [] dump_stack+0x67/0x92 > [   18.984259]  [] print_circular_bug+0x1aa/0x200 > [   18.984261]  [] __lock_acquire+0x10fc/0x1260 > [   18.984264]  [] lock_acquire+0xb1/0x200 > [   18.984266]  [] ? > drm_modeset_lock_all+0x40/0x120 > [   18.984267]  [] ? > drm_modeset_lock_all+0x40/0x120 > [   18.984269]  [] mutex_lock_nested+0x67/0x3c0 > [   18.984271]  [] ? > drm_modeset_lock_all+0x40/0x120 > [   18.984273]  [] ? > rcu_read_lock_sched_held+0x7f/0x90 > [   18.984276]  [] ? > kmem_cache_alloc_trace+0x248/0x2b0 > [   18.984277]  [] ? > drm_modeset_lock_all+0x25/0x120 > [   18.984279]  [] drm_modeset_lock_all+0x40/0x120 > [   18.984281]  [] > drm_fb_helper_restore_fbdev_mode_unlocked+0x2b/0x80 > [   18.984283]  [] drm_fb_helper_set_par+0x2d/0x50 > [   18.984322]  [] intel_fbdev_set_par+0x1a/0x60 > [i915] > [   18.984324]  [] fbcon_init+0x586/0x610 > [   18.984326]  [] visual_init+0xca/0x130 > [   18.984328]  [] do_bind_con_driver+0x1c1/0x3a0 > [   18.984330]  [] do_take_over_console+0x116/0x180 > [   18.984332]  [] do_fbcon_takeover+0x57/0xb0 > [   18.984334]  [] fbcon_event_notify+0x658/0x750 > [   18.984336]  [] notifier_call_chain+0x3e/0xb0 > [   18.984338]  [] > __blocking_notifier_call_chain+0x4d/0x70 > [   18.984340]  [] > blocking_notifier_call_chain+0x16/0x20 > [   18.984342]  [] fb_notifier_call_chain+0x1b/0x20 > [   18.984344]  [] register_framebuffer+0x251/0x330 > [   18.984347]  [] ? > vga_switcheroo_client_fb_set+0x5d/0x70 > [   18.984349]  [] > drm_fb_helper_initial_config+0x25f/0x3f0 > [   18.984388]  [] > intel_fbdev_initial_config+0x18/0x30 [i915] > [   18.984389]  [] async_run_entry_fn+0x48/0x150 > [   18.984391]  [] process_one_work+0x1e7/0x750 > [   18.984392]  [] ? process_one_work+0x169/0x750 > [   18.984394]  [] worker_thread+0x4b/0x4f0 > [   18.984396]  [] ? process_one_work+0x750/0x750 > [   18.984398]  [] kthread+0xef/0x110 > [   18.984401]  [] ret_from_fork+0x1f/0x40 > [   18.984402]  [] ? kthread_stop+0x2e0/0x2e0 > > Reported-by: Imre Deak Thanks, it gets rid of the problem: Tested-by: Imre Deak --Imre