From mboxrd@z Thu Jan 1 00:00:00 1970 From: Austin S Hemmelgarn Date: Thu, 24 Sep 2015 15:21:15 +0000 Subject: Re: No more new fbdev drivers, please Message-Id: <560414EB.508@gmail.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------ms010605050604040005090601" List-Id: References: <5603EC15.9090605@ti.com> <20150924144621.40e26f0a@free-electrons.com> In-Reply-To: <20150924144621.40e26f0a@free-electrons.com> To: Thomas Petazzoni , Tomi Valkeinen Cc: Greg Kroah-Hartman , linux-fbdev , DRI Development , Sudip Mukherjee , Teddy Wang , =?UTF-8?Q?Noralf_Tr=c3=b8nnes?= , Laurent Pinchart , Dave Airlie , Daniel Vetter , "linux-kernel@vger.kernel.org" , Arnaud Patard This is a cryptographically signed message in MIME format. --------------ms010605050604040005090601 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-09-24 08:46, Thomas Petazzoni wrote: > Hello, > > On Thu, 24 Sep 2015 15:27:01 +0300, Tomi Valkeinen wrote: > >> fbdev is (more or less) maintained, but it's a deprecated framework. A= ll >> new Linux display drivers should be done on DRM. >> >> So let's not add any more new fbdev drivers. >> >> I will continue to maintain the current fbdev drivers, and I don't min= d >> adding some new features to those current drivers, as long as the amou= nt >> of code required to add the features stays sensible. >> >> I see we have three fbdev drivers in staging: xgifb, fbtft and sm750fb= , >> and the question is what to do with those. >> >> xgifb was added in 2010, and is still in staging. >> >> fbtft looks like maybe some kind of framework on top of fbdev, with >> fbtft specific subdrivers... I didn't look at it in detail, but my gut= >> says "never". > > fbtft mainly drives some very simple I2C-based or SPI-based displays, > and DRM is I believe overkill for such displays. Last time I talked > with Laurent Pinchart about such drivers, I believe he said that such > simple drivers could probably continue to use the fbdev subsystem. I have to agree, using DRM _really_ doesn't make sense for these, the=20 devices in question are (AFAIK) simple I2C or SPI connected frame-buffer = chips that are hooked up to equally simple TFT displays. There's no 3d=20 acceleration at all from what I can tell, there's _very_ limited 2d=20 acceleration, and most of the stuff that the DRM framework provides=20 call-backs for would have to be done on the CPU anyway. On top of that, = it's targeted at small embedded systems with limited memory, and the DRM = framework is by no-means lightweight (TBH, fbdev isn't really either,=20 but it's much more light weight than DRM). --------------ms010605050604040005090601 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwEAAKCC Brgwgga0MIIEnKADAgECAgMRLfgwDQYJKoZIhvcNAQENBQAweTEQMA4GA1UEChMHUm9vdCBD QTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNp Z25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcwHhcN MTUwOTIxMTEzNTEzWhcNMTYwMzE5MTEzNTEzWjBjMRgwFgYDVQQDEw9DQWNlcnQgV29UIFVz ZXIxIzAhBgkqhkiG9w0BCQEWFGFoZmVycm9pbjdAZ21haWwuY29tMSIwIAYJKoZIhvcNAQkB FhNhaGVtbWVsZ0BvaGlvZ3QuY29tMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA nQ/81tq0QBQi5w316VsVNfjg6kVVIMx760TuwA1MUaNQgQ3NyUl+UyFtjhpkNwwChjgAqfGd LIMTHAdObcwGfzO5uI2o1a8MHVQna8FRsU3QGouysIOGQlX8jFYXMKPEdnlt0GoQcd+BtESr pivbGWUEkPs1CwM6WOrs+09bAJP3qzKIr0VxervFrzrC5Dg9Rf18r9WXHElBuWHg4GYHNJ2V Ab8iKc10h44FnqxZK8RDN8ts/xX93i9bIBmHnFfyNRfiOUtNVeynJbf6kVtdHP+CRBkXCNRZ qyQT7gbTGD24P92PS2UTmDfplSBcWcTn65o3xWfesbf02jF6PL3BCrVnDRI4RgYxG3zFBJuG qvMoEODLhHKSXPAyQhwZINigZNdw5G1NqjXqUw+lIqdQvoPijK9J3eijiakh9u2bjWOMaleI SMRR6XsdM2O5qun1dqOrCgRkM0XSNtBQ2JjY7CycIx+qifJWsRaYWZz0aQU4ZrtAI7gVhO9h pyNaAGjvm7PdjEBiXq57e4QcgpwzvNlv8pG1c/hnt0msfDWNJtl3b6elhQ2Pz4w/QnWifZ8E BrFEmjeeJa2dqjE3giPVWrsH+lOvQQONsYJOuVb8b0zao4vrWeGmW2q2e3pdv0Axzm/60cJQ haZUv8+JdX9ZzqxOm5w5eUQSclt84u+D+hsCAwEAAaOCAVkwggFVMAwGA1UdEwEB/wQCMAAw VgYJYIZIAYb4QgENBEkWR1RvIGdldCB5b3VyIG93biBjZXJ0aWZpY2F0ZSBmb3IgRlJFRSBo ZWFkIG92ZXIgdG8gaHR0cDovL3d3dy5DQWNlcnQub3JnMA4GA1UdDwEB/wQEAwIDqDBABgNV HSUEOTA3BggrBgEFBQcDBAYIKwYBBQUHAwIGCisGAQQBgjcKAwQGCisGAQQBgjcKAwMGCWCG SAGG+EIEATAyBggrBgEFBQcBAQQmMCQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLmNhY2Vy dC5vcmcwMQYDVR0fBCowKDAmoCSgIoYgaHR0cDovL2NybC5jYWNlcnQub3JnL3Jldm9rZS5j cmwwNAYDVR0RBC0wK4EUYWhmZXJyb2luN0BnbWFpbC5jb22BE2FoZW1tZWxnQG9oaW9ndC5j b20wDQYJKoZIhvcNAQENBQADggIBADMnxtSLiIunh/TQcjnRdf63yf2D8jMtYUm4yDoCF++J jCXbPQBGrpCEHztlNSGIkF3PH7ohKZvlqF4XePWxpY9dkr/pNyCF1PRkwxUURqvuHXbu8Lwn 8D3U2HeOEU3KmrfEo65DcbanJCMTTW7+mU9lZICPP7ZA9/zB+L0Gm1UNFZ6AU50N/86vjQfY WgkCd6dZD4rQ5y8L+d/lRbJW7ZGEQw1bSFVTRpkxxDTOwXH4/GpQfnfqTAtQuJ1CsKT12e+H NSD/RUWGTr289dA3P4nunBlz7qfvKamxPymHeBEUcuICKkL9/OZrnuYnGROFwcdvfjGE5iLB kjp/ttrY4aaVW5EsLASNgiRmA6mbgEAMlw3RwVx0sVelbiIAJg9Twzk4Ct6U9uBKiJ8S0sS2 8RCSyTmCRhJs0vvva5W9QUFGmp5kyFQEoSfBRJlbZfGX2ehI2Hi3U2/PMUm2ONuQG1E+a0AP u7I0NJc/Xil7rqR0gdbfkbWp0a+8dAvaM6J00aIcNo+HkcQkUgtfrw+C2Oyl3q8IjivGXZqT 5UdGUb2KujLjqjG91Dun3/RJ/qgQlotH7WkVBs7YJVTCxfkdN36rToPcnMYOI30FWa0Q06gn F6gUv9/mo6riv3A5bem/BdbgaJoPnWQD9D8wSyci9G4LKC+HQAMdLmGoeZfpJzKHMYIE0TCC BM0CAQEwgYAweTEQMA4GA1UEChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNl cnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcN AQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DANBglghkgBZQMEAgMFAKCCAiEwGAYJKoZI hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUwOTI0MTUyMTE1WjBPBgkq hkiG9w0BCQQxQgRA27s+7xEebBboRPxJplVdASkkaP4wBCkqBpeX41/p8AY2PdAKNXcRHjcB Pk6EGuG9NjKJYEdxniXgK/DQKSeztDBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxEt+DCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DAN BgkqhkiG9w0BAQEFAASCAgBhj89a18DwMqQZ8STUlRwrC7L5urg9d1ojzh/7cMN3eqPKTXa7 ABwEhnGnUioENYg/ir+KTb7LnOUWWaZra7yrgwi+NTkzAO9pDVtSpiQnTYV3UH5CGRNKNvg+ AewOFtXyauS1NFEvObewKyV/dG77dbw0HkKWqiAfXvO4C1C+0r6IyYW89ghzDo+erGTd525D RWWraN6be2iAU/pV8X3z0xiW2/73X7e2vYPO25kdgvTS5DSThJnC6/9RlV65NOlfS9AKlkz/ J684629Nq1PNzAPbwZGkrvFsG/mpzUHdnmB6gBlaLbLvfAYy2BjmreUsFew/fSpwYAEZXAqS 6UDbrR9nI6THX3ZojUaEFPyzggGvxLOmreYc94ttqKs1L8OIYkd80Rqd2eD88sdZ9RoCjpKA HpnM29aBZMeAVMlUOBTX5y3rX+fawCCnf7IoN+HvknCiH7B3myPvdLsfTdDp8HkMvdKlxvit /yoBt/d5G23htf5SgCtH3rPl8VfH2Ew1AFUedPsNPpAsESY6Tbiv7S8umczp45FJInHPPC0b pyktNJYaZ3LfDFi3lSMWF0siFcebAXCR8/cGqbKrflB+s+JaQ5tMUOS7uqy91w7fdyWcl0oZ 7cgbLz4ys5rVq+ml2I4OrLAf+AAbXsYMAop228tRqTJ9uJWQCDAUOc73SwAAAAAAAA== --------------ms010605050604040005090601--