From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: "Derrick, Jonathan" To: "Busch, Keith" CC: "linux-kernel@vger.kernel.org" , "okaya@kernel.org" , "willy@infradead.org" , "liudongdong3@huawei.com" , "helgaas@kernel.org" , "poza@codeaurora.org" , "linux-pci@vger.kernel.org" , "linux-doc@vger.kernel.org" Subject: Re: [PATCH 1/2] PCI/DPC: Add 'nodpc' parameter Date: Thu, 16 Aug 2018 21:28:45 +0000 Message-ID: <1534454924.13356.1.camel@intel.com> References: <1534368400-2807-1-git-send-email-jonathan.derrick@intel.com> <20180816154940.GD5762@bombadil.infradead.org> <1534434641.17819.27.camel@intel.com> <20180816203111.GB10316@bhelgaas-glaptop.roam.corp.google.com> <1534452635.17819.53.camel@intel.com> <20180816211940.GB7400@localhost.localdomain> In-Reply-To: <20180816211940.GB7400@localhost.localdomain> Content-Type: multipart/signed; micalg=sha-1; protocol="application/x-pkcs7-signature"; boundary="=-L6lWukXHkEQXS82Ei7AQ" MIME-Version: 1.0 List-ID: --=-L6lWukXHkEQXS82Ei7AQ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2018-08-16 at 15:19 -0600, Keith Busch wrote: > On Thu, Aug 16, 2018 at 01:50:42PM -0700, Derrick, Jonathan wrote: > > It can also be disabled with setpci, but is that any less of a > > hassle? > > Genuine question to understand your point of view. >=20 > That is not a real solution, IMO. 'setpci' is good to inject things > for testing, but it changes config space without the kernel aware > that > you've done that, so it is inherently racey with other kernel threads > touching pci config space. And the kernel or platform may end up > undoing > what you had 'setpci' do anyway with no immediate way to be notified > it > was changed. It sounds like a sysfs toggle could be useful regardless of the boot parameter. --=-L6lWukXHkEQXS82Ei7AQ Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIKeTCCBOsw ggPToAMCAQICEFLpAsoR6ESdlGU4L6MaMLswDQYJKoZIhvcNAQEFBQAwbzELMAkGA1UEBhMCU0Ux FDASBgNVBAoTC0FkZFRydXN0IEFCMSYwJAYDVQQLEx1BZGRUcnVzdCBFeHRlcm5hbCBUVFAgTmV0 d29yazEiMCAGA1UEAxMZQWRkVHJ1c3QgRXh0ZXJuYWwgQ0EgUm9vdDAeFw0xMzAzMTkwMDAwMDBa Fw0yMDA1MzAxMDQ4MzhaMHkxCzAJBgNVBAYTAlVTMQswCQYDVQQIEwJDQTEUMBIGA1UEBxMLU2Fu dGEgQ2xhcmExGjAYBgNVBAoTEUludGVsIENvcnBvcmF0aW9uMSswKQYDVQQDEyJJbnRlbCBFeHRl cm5hbCBCYXNpYyBJc3N1aW5nIENBIDRBMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA 4LDMgJ3YSVX6A9sE+jjH3b+F3Xa86z3LLKu/6WvjIdvUbxnoz2qnvl9UKQI3sE1zURQxrfgvtP0b Pgt1uDwAfLc6H5eqnyi+7FrPsTGCR4gwDmq1WkTQgNDNXUgb71e9/6sfq+WfCDpi8ScaglyLCRp7 ph/V60cbitBvnZFelKCDBh332S6KG3bAdnNGB/vk86bwDlY6omDs6/RsfNwzQVwo/M3oPrux6y6z yIoRulfkVENbM0/9RrzQOlyK4W5Vk4EEsfW2jlCV4W83QKqRccAKIUxw2q/HoHVPbbETrrLmE6RR Z/+eWlkGWl+mtx42HOgOmX0BRdTRo9vH7yeBowIDAQABo4IBdzCCAXMwHwYDVR0jBBgwFoAUrb2Y ejS0Jvf6xCZU7wO94CTLVBowHQYDVR0OBBYEFB5pKrTcKP5HGE4hCz+8rBEv8Jj1MA4GA1UdDwEB /wQEAwIBhjASBgNVHRMBAf8ECDAGAQH/AgEAMDYGA1UdJQQvMC0GCCsGAQUFBwMEBgorBgEEAYI3 CgMEBgorBgEEAYI3CgMMBgkrBgEEAYI3FQUwFwYDVR0gBBAwDjAMBgoqhkiG+E0BBQFpMEkGA1Ud HwRCMEAwPqA8oDqGOGh0dHA6Ly9jcmwudHJ1c3QtcHJvdmlkZXIuY29tL0FkZFRydXN0RXh0ZXJu YWxDQVJvb3QuY3JsMDoGCCsGAQUFBwEBBC4wLDAqBggrBgEFBQcwAYYeaHR0cDovL29jc3AudHJ1 c3QtcHJvdmlkZXIuY29tMDUGA1UdHgQuMCygKjALgQlpbnRlbC5jb20wG6AZBgorBgEEAYI3FAID oAsMCWludGVsLmNvbTANBgkqhkiG9w0BAQUFAAOCAQEAKcLNo/2So1Jnoi8G7W5Q6FSPq1fmyKW3 sSDf1amvyHkjEgd25n7MKRHGEmRxxoziPKpcmbfXYU+J0g560nCo5gPF78Wd7ZmzcmCcm1UFFfIx fw6QA19bRpTC8bMMaSSEl8y39Pgwa+HENmoPZsM63DdZ6ziDnPqcSbcfYs8qd/m5d22rpXq5IGVU tX6LX7R/hSSw/3sfATnBLgiJtilVyY7OGGmYKCAS2I04itvSS1WtecXTt9OZDyNbl7LtObBrgMLh ZkpJW+pOR9f3h5VG2S5uKkA7Th9NC9EoScdwQCAIw+UWKbSQ0Isj2UFL7fHKvmqWKVTL98sRzvI3 seNC4DCCBYYwggRuoAMCAQICEzMAAKye+0C3syvSXOcAAAAArJ4wDQYJKoZIhvcNAQEFBQAweTEL MAkGA1UEBhMCVVMxCzAJBgNVBAgTAkNBMRQwEgYDVQQHEwtTYW50YSBDbGFyYTEaMBgGA1UEChMR SW50ZWwgQ29ycG9yYXRpb24xKzApBgNVBAMTIkludGVsIEV4dGVybmFsIEJhc2ljIElzc3Vpbmcg Q0EgNEEwHhcNMTcxMDE5MTcyNzI3WhcNMTgxMDE0MTcyNzI3WjBHMRowGAYDVQQDExFEZXJyaWNr LCBKb25hdGhhbjEpMCcGCSqGSIb3DQEJARYaam9uYXRoYW4uZGVycmlja0BpbnRlbC5jb20wggEi MA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQCz4TvOwEKxVEgGst/n3LricX9KG2YbHHvorBFb ggk/Wm7ZV9v/w5I5+M7SFD1CVS+MD24tlcL0mjddPXklsjPNmFb7TCXhppQMWqxwlS44iokDpHEF wx6DtwcIlfmvgPormri3U5V0gkRvnmiFSlQ2bUycWgxttAvR4sYjxLas7hE3jZJ1LJ9IxiD7VMNJ QWXSxxnOGZVf1tUTqC5uNv9wSvr8N7ZRYldP4nJ9JUFO7bazyoplxGlgxIR3+7I9TgbrUOziQCja AG6qjTBc2iB2iz6IVnzrBtQT5DR3KM6EqbMTwur8keTC11xls7lwWexzsSgt37V9UNKAqfsZPgcX AgMBAAGjggI3MIICMzAdBgNVHQ4EFgQUJRdznv8EeAa3g+3F5NKtNNctuBcwHwYDVR0jBBgwFoAU HmkqtNwo/kcYTiELP7ysES/wmPUwZQYDVR0fBF4wXDBaoFigVoZUaHR0cDovL3d3dy5pbnRlbC5j b20vcmVwb3NpdG9yeS9DUkwvSW50ZWwlMjBFeHRlcm5hbCUyMEJhc2ljJTIwSXNzdWluZyUyMENB JTIwNEEuY3JsMIGfBggrBgEFBQcBAQSBkjCBjzBpBggrBgEFBQcwAoZdaHR0cDovL3d3dy5pbnRl bC5jb20vcmVwb3NpdG9yeS9jZXJ0aWZpY2F0ZXMvSW50ZWwlMjBFeHRlcm5hbCUyMEJhc2ljJTIw SXNzdWluZyUyMENBJTIwNEEuY3J0MCIGCCsGAQUFBzABhhZodHRwOi8vb2NzcC5pbnRlbC5jb20v MAsGA1UdDwQEAwIHgDA8BgkrBgEEAYI3FQcELzAtBiUrBgEEAYI3FQiGw4x1hJnlUYP9gSiFjp9T gpHACWeB3r05lfBDAgFkAgEJMB8GA1UdJQQYMBYGCCsGAQUFBwMEBgorBgEEAYI3CgMMMCkGCSsG AQQBgjcVCgQcMBowCgYIKwYBBQUHAwQwDAYKKwYBBAGCNwoDDDBRBgNVHREESjBIoCoGCisGAQQB gjcUAgOgHAwaam9uYXRoYW4uZGVycmlja0BpbnRlbC5jb22BGmpvbmF0aGFuLmRlcnJpY2tAaW50 ZWwuY29tMA0GCSqGSIb3DQEBBQUAA4IBAQA5LNb+VnWY0V21FlNjnQ2BIb5gmlED29zwQiC5yezn 2SexgvN31129iJSkXuiBHdcVJiUAUPHYuxPRwumwbrkY6m+sYi9kIzKt+ZKNNAN4WbnavsbyRBlb cIn2E5swqD+sks8AmKivHmg+gFeboLaOf+EqVihIz1Wec1PpbX98R1t2ep7Y/81DD1fIjAWHl6Mq TJwjKQuYB01kkJdXZAGPXUQSARR1y2D1YpCkDqfGH2STaB4nenD4INSyhTGo5RV9wwTAibyrIq50 rnmvBnHTmICQVdHuIhG1gGmDLUAGqfrU3W2QJr9gkICdrTMgIEdd8s73wknaZxZKqfRxnMVQMYIC FzCCAhMCAQEwgZAweTELMAkGA1UEBhMCVVMxCzAJBgNVBAgTAkNBMRQwEgYDVQQHEwtTYW50YSBD bGFyYTEaMBgGA1UEChMRSW50ZWwgQ29ycG9yYXRpb24xKzApBgNVBAMTIkludGVsIEV4dGVybmFs IEJhc2ljIElzc3VpbmcgQ0EgNEECEzMAAKye+0C3syvSXOcAAAAArJ4wCQYFKw4DAhoFAKBdMBgG CSqGSIb3DQEJAzELBgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTE4MDgxNjIxMjg0NFowIwYJ KoZIhvcNAQkEMRYEFFN7WvrHGsbZuKjY1QSqYrKQ5fwZMA0GCSqGSIb3DQEBAQUABIIBADjnodVQ cJ3Cew8AyNb8YGRKS5IRZQZVirccgCMZjMbf5ooECpf9TD4ankWdMP3KkpDKGCd8S9zCqfp+ozXz 2fdQxG3OV3XCMpPUFiJOMT1Y4ACRFn5K1mp8X6Td5QPbOX6BLCFOpPgwMfciLJr8A8YEti0j0myk +42MlZEZZgI/nk6TpSkDtQodC53Vbh5r4AdaL9e/V3kF33lVAElfx9pl3PZvnGwDSG6PWNGlBBLo /JH0iQz16EVFtRevwe5efz5Bdnh7ZIzNimpb+mUwFG3ZBMXBfgrT4ajcGth0JvnPW5yMkZ9HCvos lOwPeuuDBux9/8uxfd1DeetlTiRqrgwAAAAAAAA= --=-L6lWukXHkEQXS82Ei7AQ--