From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Maurizio Casciano <mauriziocasciano7@gmail.com>,
mchehab@kernel.org, linux-media@vger.kernel.org,
bingbu.cao@amd.com, jacopo.mondi@ideasonboard.com,
nicholas@rothemail.net, andy@kernel.org, hansg@kernel.org,
gregkh@linuxfoundation.org, linux-staging@lists.linux.dev,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 02/16] media: ov8858: support 19.2 MHz clock and CHT gain setup
Date: Sat, 3 Oct 2026 18:24:36 +0300 [thread overview]
Message-ID: <asEeNPNR30IVg31M@ashevche-desk.local> (raw)
In-Reply-To: <asACRblly0PJOiyF@kekkonen.localdomain>
On Fri, Oct 02, 2026 at 10:13:09PM +0300, Sakari Ailus wrote:
> On Fri, Oct 02, 2026 at 10:14:29AM +0300, Andy Shevchenko wrote:
...
> > > > +#define OV8858_LINK_FREQ (360 * HZ_PER_MHZ)
> > > > +#define OV8858_XVCLK_FREQ_24MHZ 24000000
> > > > +#define OV8858_XVCLK_FREQ_19_2MHZ 19200000
> > >
> > > Why to use HZ_PER_MHZ for LINK_FREQ but not the rest?
> >
> > Because we do not do floats in the kernel. And hence for the consistency's
> > sake.
>
> Floating point operations won't end up in generated code even if you have
> floating point numbers here -- it's an integer constant.
Theoretically there is a room of misinterpretation, not every float number can
be represented as finite binary sequence, meaning that it might be off-by-one
or higher magnitude of difference in the desired and compiled values.
So it is better to avoid floats even on compile-time.
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-10-03 15:24 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-02 14:53 [PATCH v7 00/16] media: Add Yoga Book camera support Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 01/16] media: ov8858: Extract digital gain programming Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 02/16] media: ov8858: support 19.2 MHz clock and CHT gain setup Maurizio Casciano
2026-09-03 4:42 ` Andy Shevchenko
2026-10-01 20:00 ` Sakari Ailus
2026-10-02 7:14 ` Andy Shevchenko
2026-10-02 9:17 ` Maurizio Casciano
2026-10-02 19:13 ` Sakari Ailus
2026-10-03 15:24 ` Andy Shevchenko [this message]
2026-10-02 9:17 ` Maurizio Casciano
2026-10-02 10:31 ` Dan Carpenter
[not found] ` <CAO7O_xhgUqCuHZUiBpjL_jsMrzG2grwkNzdsdBW9SiHW=rTfCA@mail.gmail.com>
2026-10-02 10:35 ` Dan Carpenter
2026-10-02 12:37 ` Maurizio Casciano
2026-10-02 13:15 ` Dan Carpenter
2026-09-02 14:53 ` [PATCH v7 03/16] media: ov2740: Use C99 initializers for ACPI IDs Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 04/16] media: ov2740: Add OVTI2740 ACPI ID Maurizio Casciano
2026-09-03 5:35 ` Andy Shevchenko
2026-09-02 14:53 ` [PATCH v7 05/16] media: ov8858: Add INT3477 " Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 06/16] media: intel: ipu-bridge: Add Yoga Book camera sensors Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 07/16] media: atomisp: Add Yoga Book camera configuration Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 08/16] media: ov2740: support 288 MHz link frequency Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 09/16] media: intel: ipu-bridge: allow sensor-specific link frequencies Maurizio Casciano
2026-09-03 7:01 ` Andy Shevchenko
2026-10-01 20:03 ` Sakari Ailus
2026-10-02 9:18 ` Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 10/16] media: atomisp: derive CSI-2 timing from sensor link frequency Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 11/16] media: atomisp: provide Yoga Book OV2740 " Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 12/16] media: ov2740: release group hold after gain write errors Maurizio Casciano
2026-10-01 20:06 ` Sakari Ailus
2026-10-02 9:18 ` Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 13/16] media: ov2740: add manual white balance controls Maurizio Casciano
2026-09-02 14:53 ` [PATCH v7 14/16] media: atomisp: Use struct v4l2_area for padding Maurizio Casciano
2026-09-03 7:04 ` Andy Shevchenko
2026-09-02 14:53 ` [PATCH v7 15/16] media: atomisp: allow raw Bayer capture Maurizio Casciano
2026-09-03 7:12 ` Andy Shevchenko
2026-09-02 14:53 ` [PATCH v7 16/16] media: i2c: Add WV517S lens actuator driver Maurizio Casciano
2026-09-03 4:44 ` [PATCH v7 00/16] media: Add Yoga Book camera support Andy Shevchenko
2026-09-03 5:37 ` Andy Shevchenko
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