spi: spi-sun4i: fix early activation

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[ Upstream commit fb98bd0a13 ]

The SPI interface is activated before the CPOL setting is applied. In
that moment, the clock idles high and CS goes low. After a short delay,
CPOL and other settings are applied, which may cause the clock to change
state and idle low. This transition is not part of a clock cycle, and it
can confuse the receiving device.

To prevent this unexpected transition, activate the interface while CPOL
and the other settings are being applied.

Signed-off-by: Alessandro Grassi <alessandro.grassi@mailbox.org>
Link: https://patch.msgid.link/20250502095520.13825-1-alessandro.grassi@mailbox.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Alessandro Grassi 2025-05-02 11:55:20 +02:00 • committed by Greg Kroah-Hartman

parent 4916624695

commit 128b5f0206

1 changed files with 4 additions and 1 deletions

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drivers/spi/spi-sun4i.c

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