Hi, Tony Lindgren <tony@xxxxxxxxxxx> writes: > * Felipe Balbi <balbi@xxxxxxxxxx> [161208 09:52]: >> >> Hi, >> >> Tony Lindgren <tony@xxxxxxxxxxx> writes: >> > * Felipe Balbi <balbi@xxxxxxxxxx> [161208 01:45]: >> >> >> >> Hi, >> >> >> >> Tony Lindgren <tony@xxxxxxxxxxx> writes: >> >> > Somehow starting with v4.9-rc7 there have been imprecise >> >> >> >> There's nothing touching dwc3 since v4.9-rc5. >> > >> > Right, nothing obvious has changed. I think it's just a slight timing >> > change in the code that started triggering it. >> >> could be >> >> >> > external aborts on omap5-uevm dwc3 controller. I have not been >> >> > able to bisect what exactly triggered this as it does not always >> >> > happen. It seems that something changed with probing that >> >> > now exposes the issue: >> >> > >> >> > Unhandled fault: imprecise external abort (0x1406) at 0x00000000 >> >> >> >> hmmm, clock disabled... dwc3-omap shouldn't have pm runtime at all. >> > >> > It does for the interconnect target module clkctrl register via PM >> > runtime. That's the "usb_otg_ss" module. >> >> but that's all hidden in omap_device.c, we don't touch it from driver >> perspective. > > The call to pm_runtime_get_sync() in dwc3_omap_probe() will use it. right, but there's no runtime suspend until ->remove(). IOW, after pm_runtime_get_sync(), all necessary clocks should already be enabled. If they aren't, there's either an erratum or a bug in drivers/clk/ti/ > Is there also some dwc3 internal clock? If we assume the usb_otg_ss > module is properly enabled it could be some dwc3 internal clock not > enabled? no extra clocks. > We do have a srst_udelay needed for enabling musb controller for some > SoCs, I'll check if that's the case here. okay >> >> > Fix the issue by making sure the dwc3 interrupts are disabled >> >> > before we call devm_request_threaded_irq(). >> >> >> >> that should already be the case. Are you sure that register isn't zero >> >> in probe? >> > >> > Looks like irq0_status = 0 and irqmisc_status = 0x2121. Also just >> > clearing irqmisc with dwc3_omap_write_irqmisc_clr(omap, 0xffffffff) >> > stops the issue from happening. >> > >> > There is some deferred probing happening but irqmisc is always 0x2121. >> >> some spurious irq status from ROM code, perhaps? Are you not resetting >> usb_otg_ss hwmod? We shouldn't have any pending interrupts when we get >> to probe(), if we do have them, then we need an erratum for it. > > I have u-boot use it to download the kernel and that is probably using > the ROM code USB support. is IRQ status already 0x2121 from u-boot prompt? >> You could try making usb_otg_ss is reset by hwmod. It would also be good >> to check other OMAP-ish devices sporting dwc3 (DRA7x, AM437x, AM57x) if >> they have the same behavior. > > It should be reset by default by hwmod. in which case, IRQ status should be reset to 0. -- balbi -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
