lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 10 Nov 2015 08:50:53 +0800 From: Yingjoe Chen <yingjoe.chen@...iatek.com> To: Andy Shevchenko <andy.shevchenko@...il.com> CC: Liguo Zhang <liguo.zhang@...iatek.com>, Xudong Chen <xudong.chen@...iatek.com>, <srv_heupstream@...iatek.com>, Wolfram Sang <wsa@...-dreams.de>, Sascha Hauer <s.hauer@...gutronix.de>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, <linux-mediatek@...ts.infradead.org>, <linux-i2c@...r.kernel.org>, Matthias Brugger <matthias.bgg@...il.com>, "Eddie Huang" <eddie.huang@...iatek.com>, linux-arm Mailing List <linux-arm-kernel@...ts.infradead.org> Subject: Re: [PATCH v2 1/2] i2c: mediatek: add i2c first write then read optimization On Mon, 2015-11-09 at 16:25 +0200, Andy Shevchenko wrote: > On Mon, Nov 9, 2015 at 7:43 AM, Liguo Zhang <liguo.zhang@...iatek.com> wrote: > > For platform with auto restart support, between every transfer, > > i2c controller will trigger an interrupt and SW need to handle > > it to start new transfer. When doing write-then-read transfer, > > instead of restart mechanism, using WRRD mode to have controller > > send both transfer in one request to reduce latency. > > > > @@ -518,6 +529,16 @@ static int mtk_i2c_transfer(struct i2c_adapter *adap, > > if (ret) > > return ret; > > > > + i2c->auto_restart = i2c->dev_comp->auto_restart; > > + > > + /* checking if we can skip restart and optimize using WRRD mode */ > > + if (i2c->auto_restart && num == 2) { > > + if (!(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD) && > > + msgs[0].addr == msgs[1].addr) { > > Nitpick (optional): > > ((msgs[0].flags & msgs[1].flags) & I2C_M_RD) > ? These 2 check for different conditions. The original one check the first one must NOT set I2C_M_RD, but second one must set I2C_M_RD. Joe.C -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists