linux-kernel - Re: [PATCH v1 1/1] regmap: Synchronize cache for the page selector

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Message-ID: <Z0COr-MXJTNwF9xv@smile.fi.intel.com>
Date: Fri, 22 Nov 2024 16:01:19 +0200
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: linux-kernel@...r.kernel.org
Cc: Mark Brown <broonie@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	"Rafael J. Wysocki" <rafael@...nel.org>
Subject: Re: [PATCH v1 1/1] regmap: Synchronize cache for the page selector

On Fri, Nov 22, 2024 at 03:47:34PM +0200, Andy Shevchenko wrote:
> If the selector register is represented in each page, its value
> in accordance to the debugfs is stale because it gets synchronized
> only after the real page switch happens. Synchronize cache for
> the page selector.
> 
> Before (offset followed by hexdump, the first byte is selector):
> 
>     // Real registers
>     18: 05 ff 00 00 ff 0f 00 00 f0 00 00 00
>     ...
>     // Virtual (per port)
>     40: 05 ff 00 00 e0 e0 00 00 00 00 00 1f
>     50: 00 ff 00 00 e0 e0 00 00 00 00 00 1f
>     60: 01 ff 00 00 ff ff 00 00 00 00 00 00
>     70: 02 ff 00 00 cf f3 00 00 00 00 00 0c
>     80: 03 ff 00 00 00 00 00 00 00 00 00 ff
>     90: 04 ff 00 00 ff 0f 00 00 f0 00 00 00
> 
> After:
> 
>     // Real registers
>     18: 05 ff 00 00 ff 0f 00 00 f0 00 00 00
>     ...
>     // Virtual (per port)
>     40: 00 ff 00 00 e0 e0 00 00 00 00 00 1f
>     50: 01 ff 00 00 e0 e0 00 00 00 00 00 1f
>     60: 02 ff 00 00 ff ff 00 00 00 00 00 00
>     70: 03 ff 00 00 cf f3 00 00 00 00 00 0c
>     80: 04 ff 00 00 00 00 00 00 00 00 00 ff
>     90: 05 ff 00 00 ff 0f 00 00 f0 00 00 00

Oh, while it works in my case, it is not the final (*) version I have!
Scratch this, I'll send a v2.

*) it has better check for the selector to be present in the virtual window.

-- 
With Best Regards,
Andy Shevchenko