From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Fri, 24 Apr 2015 13:40:35 +0000 Subject: Re: simple framebuffer slower by factor of 20, on socfpga (arm) platform Message-Id: <553A47D3.2070107@ti.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="klwRfHd3PBXfSr1Lid5AjRKreBdEVEFsx" List-Id: References: <20150407121247.GA29497@amd> <20150409110634.GA27407@amd> <552660C7.4020805@ti.com> <552663C2.70308@ti.com> <55277650.8070607@codeaurora.org> <20150424132923.GA11729@amd> In-Reply-To: <20150424132923.GA11729@amd> To: Pavel Machek , Archit Taneja Cc: Geert Uytterhoeven , Marek Vasut , kernel list , Dinh Nguyen , Jean-Christophe PLAGNIOL-VILLARD , Grant Likely , Rob Herring , Jingoo Han , Rob Clark , Linux Fbdev development list , "devicetree@vger.kernel.org" , shc_work@mail.ru, linux@arm.linux.org.uk, hsweeten@visionengravers.com --klwRfHd3PBXfSr1Lid5AjRKreBdEVEFsx Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 24/04/15 16:29, Pavel Machek wrote: > Hi! >=20 > On Fri 2015-04-10 12:35:52, Archit Taneja wrote: >>> That said, if the fb is in RAM, and is only written by the CPU, I thi= nk >>> a normal memcpy() for fb_memcpy_fromfb() should be fine... >> >> I didn't test for performance regressions when I posted this patch. >> >> A look at _memcpy_fromio in arch/arm/kernel/io.c shows that readb() is= used >> all the time, even when the source and destination addresses are align= ed for >> larger reads to be possible. Other archs seem to use readl() or readq(= ) when >> they can. Maybe that makes memcpy_fromio slower than the implementatio= n of >> memcpy on arm? >=20 > Ok, can you prepare a patch for me to try? Or should we just revert > the original commit? The old way worked fine, afaik, so maybe we can revert. But still, isn't it more correct to use memcpy_fromio? It's (possibly) io memory we have here. Tomi --klwRfHd3PBXfSr1Lid5AjRKreBdEVEFsx Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJVOkfTAAoJEPo9qoy8lh71eYIQAJ509Sy/MlGlLPXAlAp8Q4BV SQYHOtLMcMbUykUHks7oXsEtK6lAv8qRLrByTWiIHShTR36GwwLVEyd6jgv1bNjJ BxWViPbdO3BX6KTCHunxPZwQjDFgj+fcW21HpFfahUm9CkptmH+mZsWl2xDo70iD wp2KcQGIYTcJlx2Hgy6u+ADDEbcK+v7G2USH9pwt4EPmqKMFQ/XPpIiTZ/VF9N7b mjbPLC/D+hwS+Cu9gaGABl1q3aEErQO07itjqzohqkTbTED5g/r05iSDKvhGX1eK JQ0sybBElJj7NMHfRDDY7PJ/yDFZj3F6e10vG+c8sf9GzzusIOYIvIk7yBlFKaxM ZNHSTnP8S4oky0FDUUpiKlokEunDk97iqdT1h3Gy80IXsvPw9esF0xif7n/Dml8z x2SUSSFP6rTq9PPIgypQ4FhZ556c6lGve6wQJuKIhFuOSY27F8cpRw0suRnfcShk bUt8HkxXqFKWKSrOySi/R6AllBBi1Szt567j6azfT/I/aVgPe9bGr11ndWSqIz1q DRzeRY1HnMNIv6vhrZwDJhaNbiWh2Jbi3qv09l86mRYy5eqWDk1ll5wxImImEcyJ q+f7IZGAUx//AruUYVIHyt7L/Y4N6syO3s/37LiKbJj7Y+QrOwwJHlvrKqOgA0Nv 4ACqjfaUwr2pV2rzIRXt =XViN -----END PGP SIGNATURE----- --klwRfHd3PBXfSr1Lid5AjRKreBdEVEFsx--