On Sat, 30 Apr 2022 at 20:48, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Sat, Apr 30, 2022 at 7:18 PM H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> wrote: > > > Am 30.04.2022 um 17:36 schrieb Arnd Bergmann <arnd@xxxxxxxx>: > > > > > > > > > I suppose this could be anywhere then. The backtrace seems to point > > > to re-enabling interupts in do_work_pending, so something probably > > > accessed DMA memory asynchronously. > > > > Yes. I now (or still) sometimes see the same omap l3 irq issue when plugging in/out the USB/OTG > > cable. Not with a kernel panic, but in the same driver omap_l3_smx.c. > > This happens even if the wl1251 driver is removed. > > Is this also a regression, or did it happen before the vmap-stack > change? If this only > appeared now, then this points to another bug somewhere that you > should find using > CONFIG_DMA_API_DEBUG. > > I think what is going on here is that your platform is able to detect > the broken DMA > because of the l3 interrupt handler telling the kernel about it, when > on other platforms > we would see either silent data corruption or a DMA that never reaches > its target. > I wonder if we could narrow this down by adding the possibility to use IRQ stacks in the linear map, while using vmap'ed task stacks.
