Re: SPI regression seen on ARM am335x in kernel 6.12.8 and 6.6.71

On Thu, Jan 16, 2025 at 03:21:13PM +0100, Lars Pedersen wrote:

Hi. We have discovered an SPI regression when upgrading from 6.1.99 to a newer LTS version. Same error on kernel 6.6.71 and 6.12.8.

I think we have identified the problem down to the reference clock calculation that seems to end up to zero in the spi-omap2-mcspi driver.

Also we think it relates to commit 4c6ac5446d060f0bf435ccc8bc3aa7b7b5f718ad, where OMAP2_MCSPI_MAX_FREQ is used as fallback on error. In our case it seems to hit the else case.

Snippets for device tree, spi-omap2-mcspi driver and kernel divide by zero error log with dynamic debug enabled.

If you revert the offending commit, does that solve the issue?

thanks,

greg k-h