> Robin Murphy <robin.murphy@xxxxxxx> hat am 25. Juli 2017 um 15:21 geschrieben: > > > Hi Stefan, > > On 25/07/17 06:19, Stefan Wahren wrote: > >>> With arm64 4.13-rc1 I get no eth0 device on Pi3 (openSUSE Tumbleweed). > >>> The v4.13-rc1 DT works okay with a 4.12 kernel. > >>> > >>> Possibly related: > >>> > >>> [ 15.916350] OF: /soc/usb@7e980000: could not get #phy-cells for /phy > >>> > >>> [ 16.496662] usb 1-1: new high-speed USB device number 2 using dwc2 > >>> [ 16.502988] dwc2 3f980000.usb: Cannot do DMA to address > >>> 0x00000000335da400 > >> > >> This is from SWIOTLB's map_single(), which means whatever device was > >> passed into dma_map_single() when mapping the URB had a DMA mask smaller > >> than 30 bits (or none at all), which sounds wrong and is almost > >> certainly the root of the problem (i.e. it probably wasn't the actual > >> HCD device described in DT and set up by of_dma_configure()). > > > > how can i figure out what's cause this issue (bcm283x or dwc2 specific)? > > > > The dwc2 hcd already check the DMA mask on probe [1] and i never saw a warning in error case. > > I'll admit I'm a little stumped, since the two commits to dwc2 since > 4.12 seem entirely inconsequential. > > The only way I can see this happening is if the first dma_capable() > check in swiotlb_map_page() fails, and since swiotlb_force must be set > to SWIOTLB_NOFORCE in order to print the error later, and the address > and size look reasonable, that only leaves dev->dma_mask as the culprit. > > From the subsequent fallout (which on closer inspection looks more to do > with calling into uninitialised SWIOTLB state than the arm64 DMA code > actually doing anything wrong), I'd guess dev->dma_pfn_offset is > probably 0 as well, which further points to the wrong device. Maybe > something's changed lower down in the USB core? Turning on tracing and > booting with "tp_printk trace_event=swiotlb_bounced" on the command line > should shed a bit more light on what's going on. > FWIW, i added some dev_info before and after dma_set_mask in dwc2 (error case): [ 5.471761] dwc2 3f980000.usb: before mask: FFFFFFFF [ 5.491016] dwc2 3f980000.usb: before coherent mask: FFFFFFFF [ 5.513379] dwc2 3f980000.usb: after mask: FFFFFFFF [ 5.532572] dwc2 3f980000.usb: after coherent mask: FFFFFFFF [ 5.555039] dwc2 3f980000.usb: DWC OTG Controller [ 5.575855] dwc2 3f980000.usb: new USB bus registered, assigned bus number 1 [ 5.605944] dwc2 3f980000.usb: irq 41, io mem 0x3f980000 which doesn't match the tracing outputs. > Robin. > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
