From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Summers, Stuart" Subject: Re: [PATCH 1/2] drm/i915: Re-add enable_rc6 modparam Date: Thu, 16 May 2019 15:49:19 +0000 Message-ID: <66758be0515771b27172bcf0e1e6138ff2932bce.camel@intel.com> References: <20190514164653.935-1-stuart.summers@intel.com> <155785283553.21839.2059003338244451933@skylake-alporthouse-com> <4387e52b0895d400d4e0f5c71e4c8e0a164add7c.camel@intel.com> <20190515000604.GC18687@intel.com> <87ftpeaff0.fsf@intel.com> <87mujm76ej.fsf@intel.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0690070695==" Return-path: Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id 921B689709 for ; Thu, 16 May 2019 15:56:23 +0000 (UTC) In-Reply-To: <87mujm76ej.fsf@intel.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: "Vivi, Rodrigo" , "jani.nikula@linux.intel.com" Cc: "intel-gfx@lists.freedesktop.org" List-Id: intel-gfx@lists.freedesktop.org --===============0690070695== Content-Language: en-US Content-Type: multipart/signed; micalg=sha-1; protocol="application/x-pkcs7-signature"; boundary="=-iFFJhS8e35qNBodGTDbr" --=-iFFJhS8e35qNBodGTDbr Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2019-05-16 at 18:42 +0300, Jani Nikula wrote: > On Thu, 16 May 2019, "Summers, Stuart" > wrote: > > On Thu, 2019-05-16 at 12:59 +0300, Jani Nikula wrote: > > > On Tue, 14 May 2019, Rodrigo Vivi wrote: > > > > One possibility that just came to my mind now is, what if we > > > > make > > > > this only for platforms that are still protected by > > > > is_alpha_support=3D1 > > > > (soon becoming require_force_probe=3D1) > > >=20 > > > Please don't conflate alpha_support or force_probe with > > > *anything* > > > else. > > >=20 > > > > But this is just one side of the coin... when product is out > > > > there > > > > and we want the user to debug the issue to see if it is a RC6 > > > > bug > > > > we have no way to verify that. :/ > > >=20 > > > The problem is, if it works with rc6 disabled, it doesn't prove > > > it's > > > an > > > rc6 bug either. > >=20 > > Good point. I'm not saying we should enforce a process of disabling > > RC6 > > for the platform if enable_rc6=3D0 results in success. I'm just > > saying > > having the option is useful from a debug perspective. We will still > > need to do the appropriate full analysis, including the normal code > > review process on a pre-case basis when debug involves this > > parameter. > > But the parameter itself is still useful. >=20 > The trouble starts when users figure out that enable_rc6=3D0 works > around > a particular problem they have (likely by way of disabling runtime > pm, > not directly related to rc6). You could argue this is a good thing, > but > unfortunately we generally never hear from them again, and the root > cause remains unsolved, with degraded user experience wrt power > management. So I understand the reasoning here, and agree that isn't an ideal situation. I'd also like a way to debug more efficiently. What did you think about the suggestion from Tvrtko to only apply on CONFIG_DRM_I915_DEBUG? Or we could even wrap this entirely with a CONFIG_I915_DEBUG_PM - although I'd like to suggest we still use the module parameter, we could just use the config option to hide the modparam under normal operation. Thanks, Stuart >=20 > BR, > Jani. >=20 >=20 --=-iFFJhS8e35qNBodGTDbr Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIKcTCCBOsw ggPToAMCAQICEDabxALowUBS+21KC0JI8fcwDQYJKoZIhvcNAQEFBQAwbzELMAkGA1UEBhMCU0Ux FDASBgNVBAoTC0FkZFRydXN0IEFCMSYwJAYDVQQLEx1BZGRUcnVzdCBFeHRlcm5hbCBUVFAgTmV0 d29yazEiMCAGA1UEAxMZQWRkVHJ1c3QgRXh0ZXJuYWwgQ0EgUm9vdDAeFw0xMzEyMTEwMDAwMDBa Fw0yMDA1MzAxMDQ4MzhaMHkxCzAJBgNVBAYTAlVTMQswCQYDVQQIEwJDQTEUMBIGA1UEBxMLU2Fu dGEgQ2xhcmExGjAYBgNVBAoTEUludGVsIENvcnBvcmF0aW9uMSswKQYDVQQDEyJJbnRlbCBFeHRl cm5hbCBCYXNpYyBJc3N1aW5nIENBIDRCMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA yzuW/y/g0bznz8BD48M94luFzqHaqY9yGN9H/W0J7hOVBpl0rTQJ6kZ7z7hyDb9kf2UW4ZU25alC i+q5m6NwHg+z9pcN7bQ84SSBueaYF7cXlAg7z3XyZbzSEYP7raeuWRf5fYvYzq8/uI7VNR8o/43w PtDP10YDdO/0J5xrHxnC/9/aU+wTFSVsPqxsd7C58mnu7G4VRJ0n9PG4SfmYNC0h/5fLWuOWhxAv 6MuiK7MmvTPHLMclULgJqVSqG1MbBs0FbzoRHne4Cx0w6rtzPTrzo+bTRqhruaU18lQkzBk6OnyJ UthtaDQIlfyGy2IlZ5F6QEyjItbdKcHHdjBX8wIDAQABo4IBdzCCAXMwHwYDVR0jBBgwFoAUrb2Y ejS0Jvf6xCZU7wO94CTLVBowHQYDVR0OBBYEFNpBI5xaj3GvV4M+INPjZdsMywvbMA4GA1UdDwEB /wQEAwIBhjASBgNVHRMBAf8ECDAGAQH/AgEAMDYGA1UdJQQvMC0GCCsGAQUFBwMEBgorBgEEAYI3 CgMEBgorBgEEAYI3CgMMBgkrBgEEAYI3FQUwFwYDVR0gBBAwDjAMBgoqhkiG+E0BBQFpMEkGA1Ud HwRCMEAwPqA8oDqGOGh0dHA6Ly9jcmwudHJ1c3QtcHJvdmlkZXIuY29tL0FkZFRydXN0RXh0ZXJu YWxDQVJvb3QuY3JsMDoGCCsGAQUFBwEBBC4wLDAqBggrBgEFBQcwAYYeaHR0cDovL29jc3AudHJ1 c3QtcHJvdmlkZXIuY29tMDUGA1UdHgQuMCygKjALgQlpbnRlbC5jb20wG6AZBgorBgEEAYI3FAID oAsMCWludGVsLmNvbTANBgkqhkiG9w0BAQUFAAOCAQEAp9XGgH85hk/3IuN8F4nrFd24MAoau7Uq M/of09XtyYg2dV0TIPqtxPZw4813r78WwsGIbvtO8VQ18dNktIxaq6+ym2zebqDh0z6Bvo63jKE/ HMj8oNV3ovnuo+7rGpCppcda4iVBG2CetB3WXbUVr82EzECN+wxmC4H9Rup+gn+t+qeBTaXulQfV TYOvZ0eZPO+DyC2pVv5q5+xHljyUsVqpzsw89utuO8ZYaMsQGBRuFGOncRLEOhCtehy5B5aCI571 i4dDAv9LPODrEzm3PBfrNhlp8C0skak15VXWFzNuHd00AsxXxWSUT4TG8RiAH61Ua5GXsP1BIZwl 4WjK8DCCBX4wggRmoAMCAQICEzMAAHThOHejBjRRsRQAAAAAdOEwDQYJKoZIhvcNAQEFBQAweTEL MAkGA1UEBhMCVVMxCzAJBgNVBAgTAkNBMRQwEgYDVQQHEwtTYW50YSBDbGFyYTEaMBgGA1UEChMR SW50ZWwgQ29ycG9yYXRpb24xKzApBgNVBAMTIkludGVsIEV4dGVybmFsIEJhc2ljIElzc3Vpbmcg Q0EgNEIwHhcNMTkwMTIzMTcxMTA0WhcNMjAwMTE4MTcxMTA0WjBDMRgwFgYDVQQDEw9TdW1tZXJz LCBTdHVhcnQxJzAlBgkqhkiG9w0BCQEWGHN0dWFydC5zdW1tZXJzQGludGVsLmNvbTCCASIwDQYJ KoZIhvcNAQEBBQADggEPADCCAQoCggEBAL7LpY79h4eyLdxekwAblnyPAHSCaXvVTUmnPKxWXs9g VCcf7gjGg8qg/HLCwvgGKGqtVkn2EaCKd85rqklaTp07JciV6a77qodO0yOgyz96hRVuSFAIP0UQ TXP+PuVIfYuqNSSgh2x2HzJy2DzpG12ZMldy6r2zAa6ypWevjFp5+3/mscAVNAmSHnyj838uukd/ YwrFtEG2j5l/EoijzGMRFUD0tS5eD2y0WmRfmc4xkv1Qjr8AN3ogZr4arGr+rF2F4aakLmoDUCZk PwuHX1mRETAlwqXCZa6ba8eraUCltlCb/ZiEk9UFRVLjbLNPh9IYOi+sWkS6n5CovLKAqhMCAwEA AaOCAjMwggIvMB0GA1UdDgQWBBSgeYqvLV4nBaCUzAXLr0TeMJYR5zAfBgNVHSMEGDAWgBTaQSOc Wo9xr1eDPiDT42XbDMsL2zBlBgNVHR8EXjBcMFqgWKBWhlRodHRwOi8vd3d3LmludGVsLmNvbS9y ZXBvc2l0b3J5L0NSTC9JbnRlbCUyMEV4dGVybmFsJTIwQmFzaWMlMjBJc3N1aW5nJTIwQ0ElMjA0 Qi5jcmwwgZ8GCCsGAQUFBwEBBIGSMIGPMCIGCCsGAQUFBzABhhZodHRwOi8vb2NzcC5pbnRlbC5j b20vMGkGCCsGAQUFBzAChl1odHRwOi8vd3d3LmludGVsLmNvbS9yZXBvc2l0b3J5L2NlcnRpZmlj YXRlcy9JbnRlbCUyMEV4dGVybmFsJTIwQmFzaWMlMjBJc3N1aW5nJTIwQ0ElMjA0Qi5jcnQwCwYD VR0PBAQDAgeAMDwGCSsGAQQBgjcVBwQvMC0GJSsGAQQBgjcVCIbDjHWEmeVRg/2BKIWOn1OCkcAJ Z4HevTmV8EMCAWQCAQkwHwYDVR0lBBgwFgYIKwYBBQUHAwQGCisGAQQBgjcKAwwwKQYJKwYBBAGC NxUKBBwwGjAKBggrBgEFBQcDBDAMBgorBgEEAYI3CgMMME0GA1UdEQRGMESgKAYKKwYBBAGCNxQC A6AaDBhzdHVhcnQuc3VtbWVyc0BpbnRlbC5jb22BGHN0dWFydC5zdW1tZXJzQGludGVsLmNvbTAN BgkqhkiG9w0BAQUFAAOCAQEAfyIC7rzSi6S8O+sdH384K8zyeMRJnl6vR7whl9PuEat+BkKpoxHn jQ0SFyF/cyI4lH/n938Pm3/Ctq0Z5GTldX6hhxxcLAR0qbk6AQU0Cq2nYMlZfX4FUz3FRsazbjTW 1qObcvPRUAVScaa7SRGdensvbNV++pN1XqEdc++szxo58UzPaEgDlHIe2sEIVXnFkHnJv0ikRHG3 urcA1bdj7Rac7dJBeQOQMdZEGmrWWmmbJzvk3OmoK9tKN7wcErQSdlqyYOMLesPfa7YNyLFYEJQd CC/N7V8U9yFZx8akWREb8lJYDl9KypirEsufleiew26CWrwcbmdlldDCFS6/HDGCAhcwggITAgEB MIGQMHkxCzAJBgNVBAYTAlVTMQswCQYDVQQIEwJDQTEUMBIGA1UEBxMLU2FudGEgQ2xhcmExGjAY BgNVBAoTEUludGVsIENvcnBvcmF0aW9uMSswKQYDVQQDEyJJbnRlbCBFeHRlcm5hbCBCYXNpYyBJ c3N1aW5nIENBIDRCAhMzAAB04Th3owY0UbEUAAAAAHThMAkGBSsOAwIaBQCgXTAYBgkqhkiG9w0B CQMxCwYJKoZIhvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xOTA1MTYxNTQ5MTdaMCMGCSqGSIb3DQEJ BDEWBBQIcL+W40P66P9NniyAK4lNG+EYjTANBgkqhkiG9w0BAQEFAASCAQAmFj35nusJxSZFESCX EubW9zgZ/RsrVElQQEMPOnWeAiUgQu1Hi2sTQ1V0h3Gz+DFxT61GsLlY6mMIqCOwu0+irRSJmxzF vrFgbaCS3HAhvjB4Ij6ZMQylYB2J3HGRmg3i7qCywA+ibemepP0NAXoHyA2bl/C6qqCMdvJZ7lGi uY7QmX2xcS+qK6JJFOc44vFTVF6VQL3XvoMoOlIl/Z+BR0o6kwYGyNCEEDfIyU5ASA3y86orNUNO A2a2s/Qd+Q6XkTWr/rDWVRm1ydR6O8NC05bCdaMcslruKRp4Rb8ndDt/ExjnwO3vTP5ZOO3FnD7G HtIJts1HqRjDiXfWJZ6YAAAAAAAA --=-iFFJhS8e35qNBodGTDbr-- --===============0690070695== Content-Type: text/plain; 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