Gregory, On Fri, Oct 16, 2015 at 1:44 PM, Herrero, Gregory <gregory.herrero@xxxxxxxxx> wrote: > I can't reproduce this issue so far but using GFP_DMA32 is obviously > wrong here, so I will replace with GFP_DMA. With that, I can definitely boot up. :) >> When I reverted this patch and tried to enable DMA descriptor >> transfers, I got no crash but got: >> >> [ 40.956331] dwc2 ff540000.usb: AHB ERROR, Channel 0 >> [ 40.961214] dwc2 ff540000.usb: hcchar 0x80b418c0, hcsplt 0x00000000 >> [ 40.967652] dwc2 ff540000.usb: hctsiz 0x60003fff, hc_dma 0x20c3b0c0 >> [ 40.974084] dwc2 ff540000.usb: Device address: 2 >> [ 40.978868] dwc2 ff540000.usb: Endpoint: 3, OUT >> [ 40.983565] dwc2 ff540000.usb: Endpoint type: ISOCHRONOUS >> [ 40.989129] dwc2 ff540000.usb: Speed: FULL >> [ 40.993392] dwc2 ff540000.usb: Max packet size: 192 >> [ 40.998434] dwc2 ff540000.usb: Data buffer length: 1152 >> [ 41.003824] dwc2 ff540000.usb: Transfer buffer: f142d000, >> Transfer DMA: 258f6000 >> [ 41.011383] dwc2 ff540000.usb: Setup buffer: (null), Setup DMA: 00000000 >> [ 41.018420] dwc2 ff540000.usb: Interval: 1 >> >> ...I haven't tried debugging that at all yet. ;) >> >> -Doug > > You may retry with GFP_DMA. This patch is needed to get correct buffer > alignment for dwc2 controller. I guess, using non correct alignment > could lead to this kind of AHB error. OK, I tried that and I didn't get the AHB error. I swear I saw descriptor DMA mode work one time, too, but then I tried again and I couldn't reproduce. I'll do more debugging Monday. Today I spent much of the day trying to figure out why sometimes when I plugged things in it didn't detect (see patches I posted). ;) -Doug -- 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
