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Date:   Thu, 12 Jan 2023 16:57:55 +0000
From:   Mark Brown <broonie@kernel.org>
To:     William Zhang <william.zhang@broadcom.com>
Cc:     Linux SPI List <linux-spi@vger.kernel.org>,
        Broadcom Kernel List <bcm-kernel-feedback-list@broadcom.com>,
        anand.gore@broadcom.com, tomer.yacoby@broadcom.com,
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        f.fainelli@gmail.com, jonas.gorski@gmail.com,
        kursad.oney@broadcom.com, dregan@mail.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 11/16] spi: bcm63xx-hsspi: Add prepend feature support
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On Wed, Jan 11, 2023 at 11:42:57AM -0800, William Zhang wrote:
> On 01/10/2023 01:18 PM, Mark Brown wrote:

> > spi_replace_transfers().

> Okay I saw this function is used by spi_split_transfers_maxsize which a few
> drivers use to limit the transfer size and it make sense.  I can come up
> something like spi_merge_transfers to be used by my driver's prepend
> function.  But it has the same issue I mentioned early as the these tx, rx
> transfers have the dependency on the order they present in the original
> transfer list for my prepend function to work.  And for the same reason, it
> won't be generally useful for other drivers.

I wouldn't be surprised if something else turned up which had similar
constraints, SPI isn't the most complex thing ever so there's a lot of
patterns in controlers that get reproduced.

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