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Date:   Tue, 30 Aug 2022 19:14:03 +0100
From:   Mark Brown <broonie@kernel.org>
To:     Wei Yongjun <weiyongjun1@huawei.com>
Cc:     Steven Rostedt <rostedt@goodmis.org>,
        Ingo Molnar <mingo@redhat.com>, linux-kernel@vger.kernel.org,
        linux-spi@vger.kernel.org
Subject: Re: [PATCH -next 2/4] spi: mockup: Add writeable tracepoint for spi
 transfer
Message-ID: <Yw5Ta8sO3fMsPLDY@sirena.org.uk>
References: <20220826144341.532265-1-weiyongjun1@huawei.com>
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On Fri, Aug 26, 2022 at 02:43:39PM +0000, Wei Yongjun wrote:

> +#define SPI_BUFSIZ_MAX		0x1000
> +
> +struct spi_msg_ctx {
> +	int ret;
> +	__u8 data[SPI_BUFSIZ_MAX];
> +};

This has a hard limit on the size of messages of only 4k on the
size of messages, that seems a bit on the low side especially
considering that the example is for a flash device.  There's also
things like firmware downloads which can easily exceed 4k.  The
driver should at the very least report this limit via the SPI
API, and probably also complain loudly if the limit is exceeded
since it's unlikely that most drivers will actually be checking
for such a low limit given how rare they are.=20

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