From: Mark Brown <broonie@kernel.org>
To: Hang Zhou <929513338@qq.com>
Cc: jonas.gorski@gmail.com, linux-spi@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] spi: bcm63xx: fix premature CS deassertion on RX-only transactions
Date: Sun, 16 Nov 2025 21:45:02 +0000 [thread overview]
Message-ID: <aRpF3jRTs23YrPgC@sirena.co.uk> (raw)
In-Reply-To: <tencent_7AC88FCB3076489A4A7E6C2163DF1ACF8D06@qq.com>
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On Mon, Nov 17, 2025 at 01:08:35AM +1100, Hang Zhou wrote:
> Fix this by writing 0xff dummy bytes into the TX FIFO for RX-only
> segments so that the number of bytes written to the FIFO matches the
> total message length seen by the controller.
Why 0xff? The core's _MUST_TX handling writes 0x00 which feels a bit
more natural. Given that this is PIO rather than DMA the memset_toio()
is going to be better than using the core (which is more for DMA).
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next prev parent reply other threads:[~2025-11-16 21:45 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-16 14:08 [PATCH v2] spi: bcm63xx: fix premature CS deassertion on RX-only transactions Hang Zhou
2025-11-16 21:45 ` Mark Brown [this message]
2025-11-17 16:53 ` Hang Zhou
2025-11-17 17:29 ` Mark Brown
2025-11-20 9:40 ` Mark Brown
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