Re: [PATCH 2/6] spi: rockchip: Preset cs-high and clk polarity in setup progress

[Jon Lin <jon.lin@rock-chips.com>]

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.