linux-kernel - Re: [PATCH v2] Input: cyttsp5 - improve error handling and remove regmap

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Message-ID: <ZTwWmHC7Wcd5iwqS@google.com>
Date:   Fri, 27 Oct 2023 12:59:20 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     James Hilliard <james.hilliard1@...il.com>
Cc:     linux-input@...r.kernel.org,
        Linus Walleij <linus.walleij@...aro.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] Input: cyttsp5 - improve error handling and remove
 regmap

Hi James,

On Tue, Oct 24, 2023 at 07:39:38PM -0600, James Hilliard wrote:
> The vendor cyttsp5 driver does not use regmap for i2c support, it
> would appear this is due to regmap not providing sufficient levels
> of control to handle various error conditions that may be present
> under some configuration/firmware variants.
> 
> To improve reliability lets refactor the cyttsp5 i2c interface to
> function more like the vendor driver and implement some of the error
> handling retry/recovery techniques present there.

Sorry but you need to elaborate more on what is missing in regmap and
how vendor code is better. In my experience vendors rarely follow kernel
development and either are not aware of the latest kernel APIs, or they
simply have the driver written to what we had in 3.x kernels and have
not really updated it since then.

> 
> As part of this rather than assuming the device is in bootloader mode
> we should first check that the device is in bootloader and only
> attempt to launch the app if it actually is in the bootloader.

I would prefer if this was split into a separate patch.

Thanks.

-- 
Dmitry