From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Subject: Re: [PATCH v2] PCI: create revision file in sysfs To: Bjorn Helgaas , Emil Velikov References: <20161101154232.6451-1-emil.l.velikov@gmail.com> <20161109165607.26322-1-emil.l.velikov@gmail.com> <20161110071327.GA30661@kroah.com> <20161110235931.GB12055@bhelgaas-glaptop.roam.corp.google.com> Cc: Bjorn Helgaas , Greg KH , ML dri-devel , Linux PCI From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Message-ID: <16411399-cb4a-127b-d71d-74bc7dfd4f3d@daenzer.net> Date: Mon, 14 Nov 2016 12:35:19 +0900 MIME-Version: 1.0 In-Reply-To: <20161110235931.GB12055@bhelgaas-glaptop.roam.corp.google.com> Content-Type: text/plain; charset=utf-8 List-ID: On 11/11/16 08:59 AM, Bjorn Helgaas wrote: > On Thu, Nov 10, 2016 at 01:14:35PM +0000, Emil Velikov wrote: >> On 10 November 2016 at 07:13, Greg KH wrote: >>> On Wed, Nov 09, 2016 at 04:56:07PM +0000, Emil Velikov wrote: >>>> From: Emil Velikov >>>> >>>> Currently the revision isn't available via sysfs/libudev thus if one >>>> wants to know the value they need to read through the config file. >>>> >>>> This in itself wakes/powers up the device, causing unwanted delays. >>>> >>>> There are at least two userspace components which could make use the new >>>> file - libpciaccess and libdrm. At the moment the former will wake up >>>> _every_ PCI device for simple invocation of glxinfo [when using Mesa >>>> 10.0+ drivers]. While the latter [in association with Mesa 13.0] can >>>> lead to 2-3 second delays while starting firefox, thunderbird or >>>> chromium. > > I agree, these unwanted delays are completely unacceptable. My > question is whether we should fix them by exporting more information > from the kernel, or by changing the way the userspace components work. > > It should not take anywhere near 2 seconds to wake up a PCI device. The DRM drivers for AMD/ATI GPUs can take on the order of that to initialize, so a single wakeup might be sufficient for the described symptoms. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Michel_D=c3=a4nzer?= Subject: Re: [PATCH v2] PCI: create revision file in sysfs Date: Mon, 14 Nov 2016 12:35:19 +0900 Message-ID: <16411399-cb4a-127b-d71d-74bc7dfd4f3d@daenzer.net> References: <20161101154232.6451-1-emil.l.velikov@gmail.com> <20161109165607.26322-1-emil.l.velikov@gmail.com> <20161110071327.GA30661@kroah.com> <20161110235931.GB12055@bhelgaas-glaptop.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from netline-mail3.netline.ch (mail.netline.ch [148.251.143.178]) by gabe.freedesktop.org (Postfix) with ESMTP id D12C76E0ED for ; Mon, 14 Nov 2016 03:35:26 +0000 (UTC) In-Reply-To: <20161110235931.GB12055@bhelgaas-glaptop.roam.corp.google.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Bjorn Helgaas , Emil Velikov Cc: Bjorn Helgaas , Greg KH , ML dri-devel , Linux PCI List-Id: dri-devel@lists.freedesktop.org T24gMTEvMTEvMTYgMDg6NTkgQU0sIEJqb3JuIEhlbGdhYXMgd3JvdGU6Cj4gT24gVGh1LCBOb3Yg MTAsIDIwMTYgYXQgMDE6MTQ6MzVQTSArMDAwMCwgRW1pbCBWZWxpa292IHdyb3RlOgo+PiBPbiAx MCBOb3ZlbWJlciAyMDE2IGF0IDA3OjEzLCBHcmVnIEtIIDxncmVna2hAbGludXhmb3VuZGF0aW9u Lm9yZz4gd3JvdGU6Cj4+PiBPbiBXZWQsIE5vdiAwOSwgMjAxNiBhdCAwNDo1NjowN1BNICswMDAw LCBFbWlsIFZlbGlrb3Ygd3JvdGU6Cj4+Pj4gRnJvbTogRW1pbCBWZWxpa292IDxlbWlsLnZlbGlr b3ZAY29sbGFib3JhLmNvbT4KPj4+Pgo+Pj4+IEN1cnJlbnRseSB0aGUgcmV2aXNpb24gaXNuJ3Qg YXZhaWxhYmxlIHZpYSBzeXNmcy9saWJ1ZGV2IHRodXMgaWYgb25lCj4+Pj4gd2FudHMgdG8ga25v dyB0aGUgdmFsdWUgdGhleSBuZWVkIHRvIHJlYWQgdGhyb3VnaCB0aGUgY29uZmlnIGZpbGUuCj4+ Pj4KPj4+PiBUaGlzIGluIGl0c2VsZiB3YWtlcy9wb3dlcnMgdXAgdGhlIGRldmljZSwgY2F1c2lu ZyB1bndhbnRlZCBkZWxheXMuCj4+Pj4KPj4+PiBUaGVyZSBhcmUgYXQgbGVhc3QgdHdvIHVzZXJz cGFjZSBjb21wb25lbnRzIHdoaWNoIGNvdWxkIG1ha2UgdXNlIHRoZSBuZXcKPj4+PiBmaWxlIC0g bGlicGNpYWNjZXNzIGFuZCBsaWJkcm0uIEF0IHRoZSBtb21lbnQgdGhlIGZvcm1lciB3aWxsIHdh a2UgdXAKPj4+PiBfZXZlcnlfIFBDSSBkZXZpY2UgZm9yIHNpbXBsZSBpbnZvY2F0aW9uIG9mIGds eGluZm8gW3doZW4gdXNpbmcgTWVzYQo+Pj4+IDEwLjArIGRyaXZlcnNdLiBXaGlsZSB0aGUgbGF0 dGVyIFtpbiBhc3NvY2lhdGlvbiB3aXRoIE1lc2EgMTMuMF0gY2FuCj4+Pj4gbGVhZCB0byAyLTMg c2Vjb25kIGRlbGF5cyB3aGlsZSBzdGFydGluZyBmaXJlZm94LCB0aHVuZGVyYmlyZCBvcgo+Pj4+ IGNocm9taXVtLgo+IAo+IEkgYWdyZWUsIHRoZXNlIHVud2FudGVkIGRlbGF5cyBhcmUgY29tcGxl dGVseSB1bmFjY2VwdGFibGUuICBNeQo+IHF1ZXN0aW9uIGlzIHdoZXRoZXIgd2Ugc2hvdWxkIGZp eCB0aGVtIGJ5IGV4cG9ydGluZyBtb3JlIGluZm9ybWF0aW9uCj4gZnJvbSB0aGUga2VybmVsLCBv ciBieSBjaGFuZ2luZyB0aGUgd2F5IHRoZSB1c2Vyc3BhY2UgY29tcG9uZW50cyB3b3JrLgo+IAo+ IEl0IHNob3VsZCBub3QgdGFrZSBhbnl3aGVyZSBuZWFyIDIgc2Vjb25kcyB0byB3YWtlIHVwIGEg UENJIGRldmljZS4KClRoZSBEUk0gZHJpdmVycyBmb3IgQU1EL0FUSSBHUFVzIGNhbiB0YWtlIG9u IHRoZSBvcmRlciBvZiB0aGF0IHRvCmluaXRpYWxpemUsIHNvIGEgc2luZ2xlIHdha2V1cCBtaWdo dCBiZSBzdWZmaWNpZW50IGZvciB0aGUgZGVzY3JpYmVkCnN5bXB0b21zLgoKCi0tIApFYXJ0aGxp bmcgTWljaGVsIETDpG56ZXIgICAgICAgICAgICAgICB8ICAgICAgICAgICAgICAgaHR0cDovL3d3 dy5hbWQuY29tCkxpYnJlIHNvZnR3YXJlIGVudGh1c2lhc3QgICAgICAgICAgICAgfCAgICAgICAg ICAgICBNZXNhIGFuZCBYIGRldmVsb3BlcgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fXwpkcmktZGV2ZWwgbWFpbGluZyBsaXN0CmRyaS1kZXZlbEBsaXN0cy5m cmVlZGVza3RvcC5vcmcKaHR0cHM6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0 aW5mby9kcmktZGV2ZWwK