Re: [PATCH v2 2/3] usb: chipidea: imx: support disabling runtime-pm

Hello Jun,

On Fri, 5 May 2023 09:49:16 +0000
Jun Li [off-list ref] wrote:

quoted

-----Original Message-----
From: Francesco Dolcini <francesco@dolcini.it>
Sent: Friday, May 5, 2023 12:50 AM
To: Luca Ceresoli <luca.ceresoli@bootlin.com>
Cc: devicetree@vger.kernel.org; festevam@gmail.com;
gregkh@linuxfoundation.org; Jun Li [off-list ref];
kernel@pengutronix.de; linux-arm-kernel@lists.infradead.org;
dl-linux-imx [off-list ref]; linux-kernel@vger.kernel.org;
linux-usb@vger.kernel.org; peter.chen@nxp.com; robh+dt@kernel.org;
s.hauer@pengutronix.de; shawnguo@kernel.org; Krzysztof Kozlowski
[off-list ref]; Francesco Dolcini
[off-list ref]
Subject: Re: [PATCH v2 2/3] usb: chipidea: imx: support disabling runtime-pm

Hello Luca,
I guess your mail to Philippe bounced, let me try to answer since I am aware
of the issue here.

On Thu, May 04, 2023 at 06:23:12PM +0200, Luca Ceresoli wrote:  

quoted

I found this thread after several hours spent in debugging why USB host  

is  

quoted

not detecting new devices on a custom board using the iMX6ULL Colibri
SoM.

My best workaround at the moment is:  

We have the same workaround in our BSP since quite some time, see
https://git.t/
oradex.com%2Fcgit%2Fmeta-toradex-bsp-common.git%2Ftree%2Frecipes-kernel
%2Flinux%2Flinux-toradex-mainline-git%2F0002-drivers-chipidea-disable-r
untime-pm-for-imx6ul.patch&data=05%7C01%7Cjun.li%40nxp.com%7C776dc1e71a
554ee20ed908db4cbfa5aa%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C638
188158228795706%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2l
uMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=3cFsUurgKBfic
LNfRxMOErukGiMczhJREFGvaFYTH34%3D&reserved=0
 

quoted

I haven't found any follow-up patches from you, so I'm wondering whether
you have made any progress on this issue.  

You can find the latest discussion on that regard here
https://lore/.
kernel.org%2Fall%2FY1vLpaxpc5WBCuGD%40francesco-nb.int.toradex.com%2F&d
ata=05%7C01%7Cjun.li%40nxp.com%7C776dc1e71a554ee20ed908db4cbfa5aa%7C686
ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C638188158228795706%7CUnknown%7C
TWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI
6Mn0%3D%7C3000%7C%7C%7C&sdata=xgIAlY5Az9zQgOBaUTHeGJDXNIyNRmEBlcR49JOVB
sI%3D&reserved=0
 

quoted

As I see it, a quirk in the driver would make sense.  

I am not sure.

The reason this is not working is that the VBUS is not directly
connected to the SOC and the USB IP is powered in a different way (all
of that was reviewed/acked by NXP when the board was designed).  

Hi Luca,

Is your board design similar like Francesco's as below?

Possibly, but I'm afraid I can't say: I am using the Toradex Colibri
i.MX6ULL SoM, whose schematics are not public.

Best regards,
Luca

-- 
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com