From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.kapsi.fi ([217.30.184.167]:54597 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750962AbaJBFeh (ORCPT ); Thu, 2 Oct 2014 01:34:37 -0400 Message-ID: <542CE3E8.2050705@iki.fi> Date: Thu, 02 Oct 2014 08:34:32 +0300 From: Antti Palosaari MIME-Version: 1.0 To: Matthias Schwarzott , linux-media@vger.kernel.org, mchehab@osg.samsung.com Subject: Re: [PATCH V3 08/13] cx231xx: remember status of i2c port_3 switch References: <1412227265-17453-1-git-send-email-zzam@gentoo.org> <1412227265-17453-9-git-send-email-zzam@gentoo.org> In-Reply-To: <1412227265-17453-9-git-send-email-zzam@gentoo.org> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 10/02/2014 08:21 AM, Matthias Schwarzott wrote: > This is used later for is_tuner function that switches i2c behaviour for > some tuners. > > V2: Add comments about possible improvements for port_3 switch function. > > Signed-off-by: Matthias Schwarzott > --- > drivers/media/usb/cx231xx/cx231xx-avcore.c | 10 ++++++++++ > drivers/media/usb/cx231xx/cx231xx.h | 1 + > 2 files changed, 11 insertions(+) > > diff --git a/drivers/media/usb/cx231xx/cx231xx-avcore.c b/drivers/media/usb/cx231xx/cx231xx-avcore.c > index 40a6987..148b5fa 100644 > --- a/drivers/media/usb/cx231xx/cx231xx-avcore.c > +++ b/drivers/media/usb/cx231xx/cx231xx-avcore.c > @@ -1272,6 +1272,12 @@ int cx231xx_enable_i2c_port_3(struct cx231xx *dev, bool is_port_3) > > if (dev->board.dont_use_port_3) > is_port_3 = false; > + > + /* Should this code check dev->port_3_switch_enabled first */ > + /* to skip unnecessary reading of the register? */ > + /* If yes, the flag dev->port_3_switch_enabled must be initialized */ > + /* correctly. */ That multiline comment is violates Linux CodingStyle. See Documentation/CodingStyle > + > status = cx231xx_read_ctrl_reg(dev, VRT_GET_REGISTER, > PWR_CTL_EN, value, 4); > if (status < 0) > @@ -1294,6 +1300,10 @@ int cx231xx_enable_i2c_port_3(struct cx231xx *dev, bool is_port_3) > status = cx231xx_write_ctrl_reg(dev, VRT_SET_REGISTER, > PWR_CTL_EN, value, 4); > > + /* remember status of the switch for usage in is_tuner */ > + if (status >= 0) > + dev->port_3_switch_enabled = is_port_3; > + > return status; > > } > diff --git a/drivers/media/usb/cx231xx/cx231xx.h b/drivers/media/usb/cx231xx/cx231xx.h > index f03338b..8a3c97b 100644 > --- a/drivers/media/usb/cx231xx/cx231xx.h > +++ b/drivers/media/usb/cx231xx/cx231xx.h > @@ -629,6 +629,7 @@ struct cx231xx { > /* I2C adapters: Master 1 & 2 (External) & Master 3 (Internal only) */ > struct cx231xx_i2c i2c_bus[3]; > unsigned int xc_fw_load_done:1; > + unsigned int port_3_switch_enabled:1; > /* locks */ > struct mutex gpio_i2c_lock; > struct mutex i2c_lock; > I trust functionality is correct. However, I expected to see mux switching logic inside mux select() / deselect(), maybe with caching mux switch position in order to avoid I/O needed for checking mux switch position. But as I don't know that driver internals very well, I am not adding reviewed by tag, which does not mean that is wrong. It is simply because I don't know. regards Antti -- http://palosaari.fi/