Messages in this thread | | | Date | Wed, 16 Feb 2022 09:23:58 +0800 | Subject | Re: [PATCH 2/6] spi: rockchip: Preset cs-high and clk polarity in setup progress | From | Jon Lin <> |
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在 2022/2/15 20:36, Mark Brown 写道: > On Tue, Feb 15, 2022 at 11:00:54AM +0800, Jon Lin wrote: >> 在 2022/2/14 20:49, Mark Brown 写道: > >>> As covered in the documentation setup() for one device may run while >>> another is active, therefore if multiple devices are configured in the >>> same register you should use a lock to ensure there can't be multiple >>> writes. Note that the above appears to not just be setting the mode but >>> also the chip select so if you've got two SPI_CS_HIGH devices then >>> they'll both be going in and separately setting cr0. > >> Is the io_mutex in function spi_setup is good enough? > > It's not supposed to be for that but looking at the code quickly I > *think* setup() is never called with io_mutex held so it might well be > fine - you should double check though. If not you'd need to add another > lock in your driver data.
》setup() is never called with io_mutex held I think so. and I think the io_mutex is enough for me.
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