Re: [PATCH v2 2/2] spi: loongson: add bus driver for the loongson spi controller

[zhuyinbo]

在 2023/3/20 下午8:52, Mark Brown 写道:
> On Sat, Mar 18, 2023 at 02:07:16PM +0800, zhuyinbo wrote:
> > 在 2023/3/18 上午12:26, Mark Brown 写道:
> > > On Fri, Mar 17, 2023 at 04:29:50PM +0800, Yinbo Zhu wrote:
> > > As IIRC I mentioned last time setup() might be called while other
> > > transfers are happening and therefore shouldn't affect parallel
> > > operations on other devices.
> > I think add spin_lock in  transfer_one interface that should be to fix this
> > issue, Do you think so?
> No, that doesn't help if setup() reconfigures the controller while it's
> doing a transfer.  The issue is that the controller might be put into
> the wrong mode or run at the wrong speed.

sorry, I don't got that why cpu still can call setup's critical region 
when cpu call transfer_one to  transfer spi data.

when I added a spin_lock for setup and transfer_one then setup and 
transfer_one's critical region cann't be called

simultaneously as I know, because the their lock was same lock.