[Letux-kernel] [BUG]: usb: dwc3: gadget: broken on OMAP5432

Tejas Joglekar Tejas.Joglekar at synopsys.com
Wed Jan 8 10:06:34 CET 2020


Hi,
On 1/8/2020 2:29 PM, H. Nikolaus Schaller wrote:
> Hi,
> I noticed that the usb ethernet gadget driver is broken since v5.5-rc2
> and 5.4.4, but only for our OMAP5 board. Our OMAP3 boards work with
> the same tree, kernel binary and user-space (Debian Stretch).
> 
> The symptom is that I can see the interface on the host PC being
> enumerated and IP addresses etc. are set up. But a ping in either
> direction fails/times out.
> 
> After inspecting diffs I found some changes in dwc3:gadget
> and indeed omap3/twl4030 uses musb and omap5 uses dwc3.
> 
> Reverting
> 
> a7f7e61270f1 ("usb: dwc3: gadget: Fix logical condition");
> 
> on v5.5-rc makes it work again.
> 
> BTW: v4.19.90 works although it includes this logical condition fix.
> So the real difference between v4.19 and v5.5 may be elsewhere in
> newer kernels and only be revealed by the patch.
> 
> If important: my setup is running with USB2 cable and speed
> only.
> 
> So please check this and other recent dwc3 patches for introducing
> a stall of communication.
> 
Another gadget driver issue was reported by Thinh after my fix, and he has submitted a patch for the same. You can refer the discussion https://patchwork.kernel.org/patch/11292087/.
Can you check if that patch works for you ?

> BR and thanks,
> Nikolaus Schaller
> 
> 

Thanks & Regards,
 Tejas Joglekar


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