From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jani Nikula Subject: Re: [PATCH RESEND] drm/dp/mst: fix kernel oops when turning off secondary monitor Date: Wed, 15 Feb 2017 11:53:26 +0200 Message-ID: <87fujfrd9l.fsf@intel.com> References: <1487076561-2169-1-git-send-email-jani.nikula@intel.com> <20170214213843.GD11138@dvetter-linux.ger.corp.intel.com> <87r32zri60.fsf@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <87r32zri60.fsf@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Daniel Vetter Cc: Dave Airlie , intel-gfx@lists.freedesktop.org, stable@vger.kernel.org, dri-devel@lists.freedesktop.org, Dhinakaran Pandiyan List-Id: dri-devel@lists.freedesktop.org T24gV2VkLCAxNSBGZWIgMjAxNywgSmFuaSBOaWt1bGEgPGphbmkubmlrdWxhQGludGVsLmNvbT4g d3JvdGU6Cj4gT24gVHVlLCAxNCBGZWIgMjAxNywgRGFuaWVsIFZldHRlciA8ZGFuaWVsQGZmd2xs LmNoPiB3cm90ZToKPj4gT24gVHVlLCBGZWIgMTQsIDIwMTcgYXQgMDI6NDk6MjFQTSArMDIwMCwg SmFuaSBOaWt1bGEgd3JvdGU6Cj4+PiBGcm9tOiBQaWVycmUtTG91aXMgQm9zc2FydCA8cGllcnJl LWxvdWlzLmJvc3NhcnRAbGludXguaW50ZWwuY29tPgo+Pj4gCj4+PiAxMDAlIHJlcHJvZHVjaWJs ZSBpc3N1ZSBmb3VuZCBvbiBTS0wgU2t1bGxDYW55b24gTlVDIHdpdGggdHdvIGV4dGVybmFsCj4+ PiBEUCBkYWlzeS1jaGFpbmVkIG1vbml0b3JzIGluIERQL01TVCBtb2RlLiBXaGVuIHR1cm5pbmcg b2ZmIG9yIGNoYW5naW5nCj4+PiB0aGUgaW5wdXQgb2YgdGhlIHNlY29uZCBtb25pdG9yIHRoZSBt YWNoaW5lIHN0b3BzIHdpdGggYSBrZXJuZWwKPj4+IG9vcHMuIFRoaXMgaXNzdWUgaGFwcGVuZWQg d2l0aCA0LjguOCBhcyB3ZWxsIGFzIGRybS9kcm0taW50ZWwtbmlnaHRseS4KPj4+IAo+Pj4gVGhp cyBpc3N1ZSBpcyB0cmFjZWQgdG8gYW4gaW5jb25zaXN0ZW50IGNvbnRyb2wgZmxvdyBpbgo+Pj4g ZHJtX2RwX3VwZGF0ZV9wYXlsb2FkX3BhcnQxKCk6IHRoZSAncG9ydCcgcG9pbnRlciBpcyBzZXQg dG8gTlVMTCBhdCB0aGUKPj4+IHNhbWUgdGltZSBhcyAncmVxX3BheWxvYWQubnVtX3Nsb3RzJyBp cyBzZXQgdG8gemVybywgYnV0IHRoZSBwb2ludGVyIGlzCj4+PiBkZXJlZmVyZW5jZWQgZXZlbiB3 aGVuIHJlcV9wYXlsb2FkLm51bV9zbG90IGlzIHplcm8uCj4+PiAKPj4+IFRoZSBwcm9ibGVtYXRp YyBkZXJlZmVyZW5jZSB3YXMgaW50cm9kdWNlZCBpbiBjb21taXQgZGZkYTBkZjM0Cj4+PiAoImRy bS9tc3Q6IHJld29yayBwYXlsb2FkIHRhYmxlIGFsbG9jYXRpb24gdG8gY29uZm9ybSBiZXR0ZXIi KSBhbmQgbWF5Cj4+PiBpbXBhY3QgYWxsIHZlcnNpb25zIHNpbmNlIHYzLjE4Cj4+PiAKPj4+IFRo ZSBmaXggc3VnZ2VzdGVkIGJ5IENocmlzIFdpbHNvbiByZW1vdmVzIHRoZSBrZXJuZWwgb29wcyBh bmQgd2FzIGZvdW5kIHRvCj4+PiB3b3JrIHdlbGwgYWZ0ZXIgMTBtbiBvZiBtb25rZXktdGVzdGlu ZyB3aXRoIHRoZSBzZWNvbmQgbW9uaXRvciBwb3dlciBhbmQKPj4+IGlucHV0IGJ1dHRvbnMKPj4+ IAo+Pj4gQnVnemlsbGE6IGh0dHBzOi8vYnVncy5mcmVlZGVza3RvcC5vcmcvc2hvd19idWcuY2dp P2lkPTk4OTkwCj4+PiBGaXhlczogZGZkYTBkZjM0MjY0ICgiZHJtL21zdDogcmV3b3JrIHBheWxv YWQgdGFibGUgYWxsb2NhdGlvbiB0byBjb25mb3JtIGJldHRlci4iKQo+Pj4gQ2M6IERhdmUgQWly bGllIDxhaXJsaWVkQHJlZGhhdC5jb20+Cj4+PiBDYzogQ2hyaXMgV2lsc29uIDxjaHJpc0BjaHJp cy13aWxzb24uY28udWs+Cj4+PiBDYzogTmF0aGFuIEQgQ2lvYmFudSA8bmF0aGFuLmQuY2lvYmFu dUBsaW51eC5pbnRlbC5jb20+Cj4+PiBDYzogRGhpbmFrYXJhbiBQYW5kaXlhbiA8ZGhpbmFrYXJh bi5wYW5kaXlhbkBpbnRlbC5jb20+Cj4+PiBDYzogU2VhbiBQYXVsIDxzZWFucGF1bEBjaHJvbWl1 bS5vcmc+Cj4+PiBDYzogPHN0YWJsZUB2Z2VyLmtlcm5lbC5vcmc+ICMgdjMuMTgrCj4+PiBUZXN0 ZWQtYnk6IE5hdGhhbiBEIENpb2JhbnUgPG5hdGhhbi5kLmNpb2JhbnVAbGludXguaW50ZWwuY29t Pgo+Pj4gUmV2aWV3ZWQtYnk6IERoaW5ha2FyYW4gUGFuZGl5YW4gPGRoaW5ha2FyYW4ucGFuZGl5 YW5AaW50ZWwuY29tPgo+Pj4gU2lnbmVkLW9mZi1ieTogUGllcnJlLUxvdWlzIEJvc3NhcnQgPHBp ZXJyZS1sb3Vpcy5ib3NzYXJ0QGxpbnV4LmludGVsLmNvbT4KPj4+IFNpZ25lZC1vZmYtYnk6IEph bmkgTmlrdWxhIDxqYW5pLm5pa3VsYUBpbnRlbC5jb20+Cj4+Cj4+IFlvdSBoYXogZHJtLW1pc2Mg Y29tbWl0IHJpZ2h0cywgcGxzIHVzZSB0aGVtIDotKQo+Cj4gU3VyZSwgSSBqdXN0IHdhbnRlZCB0 byBoYXZlIGEgZnJlc2ggQ0kgcnVuIG9uIHRoaXMuCj4KPj4gU2luY2UgaXQgZG9lc24ndCBoYXZl IGRlcHMsIHByb2JhYmx5IHNpbXBsZXN0IHRvIHNtYXNoIGludG8gZHJtLW1pc2MtZml4ZXMKPj4g YW5kIHRoZW4gc2VuZCBhIHB1bGwgcmVxIHRvIERhdmUgcmlnaHQgYXdheS4gSWYgeW91IHdhbnQs IHlvdSBjYW4gcm9sbAo+PiAtZml4ZXMgZm9yd2FyZCB0byAtcmM4IHdoaWxlIGF0IGl0Lgo+Cj4g V2lsbCBkby4KCkFuZCBwdXNoZWQgdG8gZHJtLW1pc2MtZml4ZXMsIHRoYW5rcyBmb3IgdGhlIHBh dGNoLCByZXZpZXcgYW5kIHRlc3RpbmcuCgpCUiwKSmFuaS4KCgoKLS0gCkphbmkgTmlrdWxhLCBJ bnRlbCBPcGVuIFNvdXJjZSBUZWNobm9sb2d5IENlbnRlcgpfX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fXwpJbnRlbC1nZnggbWFpbGluZyBsaXN0CkludGVsLWdm eEBsaXN0cy5mcmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFp bG1hbi9saXN0aW5mby9pbnRlbC1nZngK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com ([134.134.136.100]:12181 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751633AbdBOJx3 (ORCPT ); Wed, 15 Feb 2017 04:53:29 -0500 From: Jani Nikula To: Daniel Vetter Cc: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, stable@vger.kernel.org, Dhinakaran Pandiyan , Dave Airlie Subject: Re: [Intel-gfx] [PATCH RESEND] drm/dp/mst: fix kernel oops when turning off secondary monitor In-Reply-To: <87r32zri60.fsf@intel.com> References: <1487076561-2169-1-git-send-email-jani.nikula@intel.com> <20170214213843.GD11138@dvetter-linux.ger.corp.intel.com> <87r32zri60.fsf@intel.com> Date: Wed, 15 Feb 2017 11:53:26 +0200 Message-ID: <87fujfrd9l.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: stable-owner@vger.kernel.org List-ID: On Wed, 15 Feb 2017, Jani Nikula wrote: > On Tue, 14 Feb 2017, Daniel Vetter wrote: >> On Tue, Feb 14, 2017 at 02:49:21PM +0200, Jani Nikula wrote: >>> From: Pierre-Louis Bossart >>> >>> 100% reproducible issue found on SKL SkullCanyon NUC with two external >>> DP daisy-chained monitors in DP/MST mode. When turning off or changing >>> the input of the second monitor the machine stops with a kernel >>> oops. This issue happened with 4.8.8 as well as drm/drm-intel-nightly. >>> >>> This issue is traced to an inconsistent control flow in >>> drm_dp_update_payload_part1(): the 'port' pointer is set to NULL at the >>> same time as 'req_payload.num_slots' is set to zero, but the pointer is >>> dereferenced even when req_payload.num_slot is zero. >>> >>> The problematic dereference was introduced in commit dfda0df34 >>> ("drm/mst: rework payload table allocation to conform better") and may >>> impact all versions since v3.18 >>> >>> The fix suggested by Chris Wilson removes the kernel oops and was found to >>> work well after 10mn of monkey-testing with the second monitor power and >>> input buttons >>> >>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98990 >>> Fixes: dfda0df34264 ("drm/mst: rework payload table allocation to conform better.") >>> Cc: Dave Airlie >>> Cc: Chris Wilson >>> Cc: Nathan D Ciobanu >>> Cc: Dhinakaran Pandiyan >>> Cc: Sean Paul >>> Cc: # v3.18+ >>> Tested-by: Nathan D Ciobanu >>> Reviewed-by: Dhinakaran Pandiyan >>> Signed-off-by: Pierre-Louis Bossart >>> Signed-off-by: Jani Nikula >> >> You haz drm-misc commit rights, pls use them :-) > > Sure, I just wanted to have a fresh CI run on this. > >> Since it doesn't have deps, probably simplest to smash into drm-misc-fixes >> and then send a pull req to Dave right away. If you want, you can roll >> -fixes forward to -rc8 while at it. > > Will do. And pushed to drm-misc-fixes, thanks for the patch, review and testing. BR, Jani. -- Jani Nikula, Intel Open Source Technology Center