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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


On Tue, Mar 21, 2023 at 10:54:32AM +0800, zhuyinbo wrote:
> 在 2023/3/20 下午8:52, Mark Brown 写道:

> > 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.

Think what happens if the two SPI devices have different configurations
- for example, a different SPI mode.  The register state won't be
corrupted but the devices will still end up seeing misconfigured SPI

Attachment: signature.asc
Description: PGP signature

[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux