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From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Thu, 4 May 2017 17:22:23 +0200
Message-ID: <CAMuHMdUFwOYsC-iYY7D0EYuTeXsGeQ7btyqt-T8_LF3zZ7k_jg@mail.gmail.com>
Subject: Re: [PATCH v4 16/27] rcar-vin: add functions to manipulate Gen3 CHSEL value
To: Sakari Ailus <sakari.ailus@iki.fi>
Cc: =?UTF-8?Q?Niklas_S=C3=B6derlund?=
        <niklas.soderlund+renesas@ragnatech.se>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Hans Verkuil <hverkuil@xs4all.nl>,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        Fukawa <tomoharu.fukawa.eb@renesas.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>,
        Kieran Bingham <kieran.bingham@ideasonboard.com>
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Hi Sakari,

On Thu, May 4, 2017 at 4:45 PM, Sakari Ailus <sakari.ailus@iki.fi> wrote:
>> --- a/drivers/media/platform/rcar-vin/rcar-dma.c
>> +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
>> @@ -16,6 +16,7 @@
>>
>>  #include <linux/delay.h>
>>  #include <linux/interrupt.h>
>> +#include <linux/pm_runtime.h>
>>
>>  #include <media/videobuf2-dma-contig.h>
>>
>> @@ -1240,3 +1241,45 @@ int rvin_dma_probe(struct rvin_dev *vin, int irq)
>>
>>       return ret;
>>  }
>> +
>> +/* -----------------------------------------------------------------------------
>> + * Gen3 CHSEL manipulation
>> + */
>> +
>> +int rvin_set_chsel(struct rvin_dev *vin, u8 chsel)
>> +{
>> +     u32 ifmd;
>> +
>> +     pm_runtime_get_sync(vin->dev);
>
> Can this fail? Just wondering.

In theory, yes.
In practice, no, unless the system is completely broken.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds