From mboxrd@z Thu Jan 1 00:00:00 1970 From: Erik Slagter Subject: RE: [PATCH] amd76x_pm: C3 powersaving for AMD K7 Date: Fri, 03 Feb 2006 10:35:12 +0100 Message-ID: <1138959312.18273.14.camel@localhost.localdomain> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=sha1; protocol="application/x-pkcs7-signature"; boundary="=-D7cU+S1zykSXwZgwDR0R" Return-path: Received: from erik-slagter.demon.nl ([83.161.107.130]:50361 "EHLO artemis.slagter.name") by vger.kernel.org with ESMTP id S932200AbWBCJfR (ORCPT ); Fri, 3 Feb 2006 04:35:17 -0500 Received: from skylla.slagter.name (skylla.slagter.name [172.31.4.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "skylla.slagter.name", Issuer "CA Cert Signing Authority" (verified OK)) by artemis.slagter.name (Postfix) with ESMTP id 2C6DE1A34004 for ; Fri, 3 Feb 2006 10:35:16 +0100 (CET) In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org --=-D7cU+S1zykSXwZgwDR0R Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Fri, 2006-02-03 at 03:45 -0500, Brown, Len wrote: > >... I disagree with Len in two points: > >- I cannot see a problem witch cache snooping. > > The AMD-768 docs clearly > > states that trying to snoop the cache while in C3 is a resume event. >=20 > Certainly the BIOS writer also had access to that document, plus > documents we do not see, yet they decided NOT to enable C2/C3. You are probably right, but I remain suspicious that the BIOS writers simply didn't want to go through the trouble of implementing and testing the whole thing, presumable because: - who wants to have power saving on a dual processor board anyway (well, I do, but that's just me) - every line of code takes time to write and test and debug, it wouldn't quite be the first occurrence of buggy or marginal "firmware", have a look at some harddisks :-( If I remember correctly there was some sort of windows driver supplied with the board to enable power saving. This would suggest that in principle there is no reason it cannot work. > Who defines the "right way"? Is it guaranteed to work on all > models and all configurations? Exactly what is the reward > for the cost we'd be paying and the risk we'd be taking? The advantage is that we're talking about only 1.5 chipset here with very few revisions. Okay, this still leaves the board manufacturer that can do what they want. > If somebody from AMD steps forth and says that hey, their hardware > is broken if used in the standard way, but that this "logic around" > is a valid model-specific workaround -- then we have something > that MAYBE we can work with. Yeah, that would be nice. But I guess _someone_ will have to poke them a bit first... --=-D7cU+S1zykSXwZgwDR0R Content-Type: application/x-pkcs7-signature; name=smime.p7s Content-Disposition: attachment; filename=smime.p7s Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIILzCCAnIw ggHboAMCAQICAw/xBDANBgkqhkiG9w0BAQQFADBiMQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhh d3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVt YWlsIElzc3VpbmcgQ0EwHhcNMDUxMTI5MTc0MTQ0WhcNMDYxMTI5MTc0MTQ0WjBqMRAwDgYDVQQE EwdTbGFndGVyMRUwEwYDVQQqEwxFcmlrIE1hcnRpam4xHTAbBgNVBAMTFEVyaWsgTWFydGlqbiBT bGFndGVyMSAwHgYJKoZIhvcNAQkBFhFlcmlrQHNsYWd0ZXIubmFtZTCBnzANBgkqhkiG9w0BAQEF AAOBjQAwgYkCgYEAtYqGuTSGbsTHZPiKQnNmvpVaxVuBZS6rV5xuKD47J9hz8Vq3Xh4PpuGYNW5L vevp80oj6sYAhNuU380UNRqALFaer8MtG6fXpvBgq+MCxVQzMyYxAnopqWlZQIUQNQX9wZmI0gVv gY6vwcXRBXkMyrzm41dy4oFwh+PTj3U+xwcCAwEAAaMuMCwwHAYDVR0RBBUwE4ERZXJpa0BzbGFn dGVyLm5hbWUwDAYDVR0TAQH/BAIwADANBgkqhkiG9w0BAQQFAAOBgQCf5+l4khcSjUOL8WcuJ7Q1 eXhSPe0VJEsHSfVJCNFmfFZFiGZNwQRliOuGFxSy+uPb8ZVIZ3cBIen/K0k2hWS6pCiDm3xNdkFU mhWsibmyMoc91I0Re2ZWPmL6isxiyr56Qv7vNz2UHSinLJr/QtsvRv/RKFlcO1gm1wsCOPkyITCC AnIwggHboAMCAQICAw/xBDANBgkqhkiG9w0BAQQFADBiMQswCQYDVQQGEwJaQTElMCMGA1UEChMc VGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZy ZWVtYWlsIElzc3VpbmcgQ0EwHhcNMDUxMTI5MTc0MTQ0WhcNMDYxMTI5MTc0MTQ0WjBqMRAwDgYD VQQEEwdTbGFndGVyMRUwEwYDVQQqEwxFcmlrIE1hcnRpam4xHTAbBgNVBAMTFEVyaWsgTWFydGlq biBTbGFndGVyMSAwHgYJKoZIhvcNAQkBFhFlcmlrQHNsYWd0ZXIubmFtZTCBnzANBgkqhkiG9w0B AQEFAAOBjQAwgYkCgYEAtYqGuTSGbsTHZPiKQnNmvpVaxVuBZS6rV5xuKD47J9hz8Vq3Xh4PpuGY NW5Lvevp80oj6sYAhNuU380UNRqALFaer8MtG6fXpvBgq+MCxVQzMyYxAnopqWlZQIUQNQX9wZmI 0gVvgY6vwcXRBXkMyrzm41dy4oFwh+PTj3U+xwcCAwEAAaMuMCwwHAYDVR0RBBUwE4ERZXJpa0Bz bGFndGVyLm5hbWUwDAYDVR0TAQH/BAIwADANBgkqhkiG9w0BAQQFAAOBgQCf5+l4khcSjUOL8Wcu J7Q1eXhSPe0VJEsHSfVJCNFmfFZFiGZNwQRliOuGFxSy+uPb8ZVIZ3cBIen/K0k2hWS6pCiDm3xN dkFUmhWsibmyMoc91I0Re2ZWPmL6isxiyr56Qv7vNz2UHSinLJr/QtsvRv/RKFlcO1gm1wsCOPky ITCCAz8wggKooAMCAQICAQ0wDQYJKoZIhvcNAQEFBQAwgdExCzAJBgNVBAYTAlpBMRUwEwYDVQQI EwxXZXN0ZXJuIENhcGUxEjAQBgNVBAcTCUNhcGUgVG93bjEaMBgGA1UEChMRVGhhd3RlIENvbnN1 bHRpbmcxKDAmBgNVBAsTH0NlcnRpZmljYXRpb24gU2VydmljZXMgRGl2aXNpb24xJDAiBgNVBAMT G1RoYXd0ZSBQZXJzb25hbCBGcmVlbWFpbCBDQTErMCkGCSqGSIb3DQEJARYccGVyc29uYWwtZnJl ZW1haWxAdGhhd3RlLmNvbTAeFw0wMzA3MTcwMDAwMDBaFw0xMzA3MTYyMzU5NTlaMGIxCzAJBgNV BAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQDEyNU aGF3dGUgUGVyc29uYWwgRnJlZW1haWwgSXNzdWluZyBDQTCBnzANBgkqhkiG9w0BAQEFAAOBjQAw gYkCgYEAxKY8VXNV+065yplaHmjAdQRwnd/p/6Me7L3N9VvyGna9fww6YfK/Uc4B1OVQCjDXAmNa LIkVcI7dyfArhVqqP3FWy688Cwfn8R+RNiQqE88r1fOCdz0Dviv+uxg+B79AgAJk16emu59l0cUq VIUPSAR/p7bRPGEEQB5kGXJgt/sCAwEAAaOBlDCBkTASBgNVHRMBAf8ECDAGAQH/AgEAMEMGA1Ud HwQ8MDowOKA2oDSGMmh0dHA6Ly9jcmwudGhhd3RlLmNvbS9UaGF3dGVQZXJzb25hbEZyZWVtYWls Q0EuY3JsMAsGA1UdDwQEAwIBBjApBgNVHREEIjAgpB4wHDEaMBgGA1UEAxMRUHJpdmF0ZUxhYmVs Mi0xMzgwDQYJKoZIhvcNAQEFBQADgYEASIzRUIPqCy7MDaNmrGcPf6+svsIXoUOWlJ1/TCG4+DYf qi2fNi/A9BxQIJNwPP2t4WFiw9k6GX6EsZkbAMUaC4J0niVQlGLH2ydxVyWN3amcOY6MIE9lX5Xa 9/eH1sYITq726jTlEBpbNU1341YheILcIRk13iSx0x1G/11fZU8xggJmMIICYgIBATBpMGIxCzAJ BgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQD EyNUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgSXNzdWluZyBDQQIDD/EEMAkGBSsOAwIaBQCgggFT MBgGCSqGSIb3DQEJAzELBgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTA2MDIwMzA5MzUxMlow IwYJKoZIhvcNAQkEMRYEFPHaR4mb9BS2BJw4wjj30l0R2JMCMHgGCSsGAQQBgjcQBDFrMGkwYjEL MAkGA1UEBhMCWkExJTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0ZC4xLDAqBgNV BAMTI1RoYXd0ZSBQZXJzb25hbCBGcmVlbWFpbCBJc3N1aW5nIENBAgMP8QQwegYLKoZIhvcNAQkQ Agsxa6BpMGIxCzAJBgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBM dGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgSXNzdWluZyBDQQIDD/EEMA0G CSqGSIb3DQEBAQUABIGAN9d0Wc3bZglZX7tAAG2wo2dRlPx4TtmXRB1CRBoPBuXxDE02AJyi/D3E mLnekCvoOynZf9zSS8xrHxe6eOaQ4xss3aR5S0XMS1v60z3Rai+XUi1375jic93iD144kaCBIzho tLwA4v9NRZPOBwij1voFNBa7+p+vsnUJAgg+K+IAAAAAAAA= --=-D7cU+S1zykSXwZgwDR0R--