On Tue, May 24, 2022 at 03:55:58PM +0100, Jon Hunter wrote: > > On 24/05/2022 13:09, Greg Kroah-Hartman wrote: > > ... > > > > I am seeing a boot regression on tegra124-jetson-tk1 and reverting the above > > > commit is fixing the problem. This also appears to impact linux-4.14.y, > > > 4.19.y and 5.4.y. > > > > > > Test results for stable-v4.9: > > > 8 builds: 8 pass, 0 fail > > > 18 boots: 16 pass, 2 fail > > > 18 tests: 18 pass, 0 fail > > > > > > Linux version: 4.9.316-rc1-gbe4ec3e3faa1 > > > Boards tested: tegra124-jetson-tk1, tegra20-ventana, > > > tegra210-p2371-2180, tegra30-cardhu-a04 > > > > > > Boot failures: tegra124-jetson-tk1 > > > > Odd. This is also in 5.10.y, right? No issues there? Are we missing > > something? > > > Actually, the more I look at this, the more I see various intermittent > reports with this and it is also impacting the mainline. > > The problem is that the commit in question is causing a ton of messages to > be printed a boot and this sometimes is causing the boot test to fail > because the boot is taking too long. The console shows ... > > [ 1233.327547] CPU0: Spectre BHB: using loop workaround > [ 1233.327795] CPU1: Spectre BHB: using loop workaround > [ 1233.328270] CPU1: Spectre BHB: using loop workaround > [ 1233.328700] CPU1: Spectre BHB: using loop workaround > [ 1233.355477] CPU2: Spectre BHB: using loop workaround > ** 7 printk messages dropped ** > [ 1233.366271] CPU0: Spectre BHB: using loop workaround > [ 1233.366580] CPU0: Spectre BHB: using loop workaround > [ 1233.366815] CPU1: Spectre BHB: using loop workaround > [ 1233.405475] CPU1: Spectre BHB: using loop workaround > [ 1233.405874] CPU0: Spectre BHB: using loop workaround > [ 1233.406041] CPU1: Spectre BHB: using loop workaround > ** 1 printk messages dropped ** > > There is a similar report of this [0] and I believe that we need a similar > fix for the above prints as well. I have reported this to Ard [1]. So I am > not sure that these Spectre BHB patches are quite ready for stable. These patches are quite small, and just enable it for this known-broken cpu type. If there is an issue enabling it for this cpu type, then we can work on that upstream, but there shouldn't be a reason to prevent this from being merged now, especially given that it is supposed to be fixing a known issue. thanks, greg k-h
