On Fri, 17 Jan 2025 at 13:32, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > 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 Hi Greg. No it doesn't solve the issue by reverting the commit. The commit isn't the regression, but it attempts to handle it in the if/else statement. Everything starts to work again if we hard code it to "mcspi->ref_clk_hz = OMAP2_MCSPI_MAX_FREQ;", so it seems like the if else statement isn't 100% foolproof (or we have missed a setting in the device tree). Thanks /Lars Pedersen
