Re: imx7: USB modem reset causes modem to not re-connect

[Alexander Stein <alexander.stein@ew.tq-group.com>]

Hello Fabio,

I had a problem regarding runtime suspend and detecting USB hub events on a 
non-removable downstream hub. Disabling runtime suspend did work as well, but
this was eventually fixed by 552ca27929ab2 ("ARM: dts: imx7: Move hsic_phy 
power domain to HSIC PHY node").
Maybe your USB device doesn't support some low power mode, but I'm not well 
versed in that area.

Best regards,
Alexander

Am Montag, 12. Dezember 2022, 20:01:25 CET schrieb Fabio Estevam:
> On Mon, Dec 12, 2022 at 3:10 PM Fabio Estevam <festevam@gmail.com> wrote:
> > Hi,
> > 
> > On an imx7d-based board running kernel 5.10.158, I noticed that a
> 
> > Quectel BG96 modem is gone after sending a reset command via AT:
> Disabling runtime pm like this:
> 
> diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c
> b/drivers/usb/chipidea/ci_hdrc_imx.c
> index 9ffcecd3058c..e2a263d583f9 100644
> --- a/drivers/usb/chipidea/ci_hdrc_imx.c
> +++ b/drivers/usb/chipidea/ci_hdrc_imx.c
> @@ -62,7 +62,6 @@ static const struct ci_hdrc_imx_platform_flag
> imx6ul_usb_data = {
>  };
> 
>  static const struct ci_hdrc_imx_platform_flag imx7d_usb_data = {
> -       .flags = CI_HDRC_SUPPORTS_RUNTIME_PM,
>  };
> 
>  static const struct ci_hdrc_imx_platform_flag imx7ulp_usb_data = {
> 
> makes the USB modem to stay connected after the reset command:
> 
> # microcom /dev/ttyUSB3
> 
> >AT+CFUN=1,1
> 
> OK
> [   31.339416] usb 2-1: USB disconnect, device number 2
> [   31.349480] option1 ttyUSB0: GSM modem (1-port) converter now
> disconnected from ttyUSB0
> [   31.358298] option 2-1:1.0: device disconnected
> [   31.366390] option1 ttyUSB1: GSM modem (1-port) converter now
> disconnected from ttyUSB1
> [   31.374883] option 2-1:1.1: device disconnected
> [   31.383359] option1 ttyUSB2: GSM modem (1-port) converter now
> disconnected from ttyUSB2
> [   31.391800] option 2-1:1.2: device disconnected
> [   31.404700] option1 ttyUSB3: GSM modem (1-port) converter now
> disconnected from ttyUSB3
> # [   31.413261] option 2-1:1.3: device disconnected
> [   36.151388] usb 2-1: new high-speed USB device number 3 using ci_hdrc
> [   36.354398] usb 2-1: New USB device found, idVendor=2c7c,
> idProduct=0296, bcdDevice= 0.00
> [   36.362768] usb 2-1: New USB device strings: Mfr=3, Product=2,
> SerialNumber=4 [   36.370031] usb 2-1: Product: Qualcomm CDMA Technologies
> MSM
> [   36.375818] usb 2-1: Manufacturer: Qualcomm, Incorporated
> [   36.381355] usb 2-1: SerialNumber: 7d1563c1
> [   36.389915] option 2-1:1.0: GSM modem (1-port) converter detected
> [   36.397679] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB0
> [   36.412591] option 2-1:1.1: GSM modem (1-port) converter detected [  
> 36.420237] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB1 [ 
>  36.434988] option 2-1:1.2: GSM modem (1-port) converter detected [  
> 36.442792] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB2 [ 
>  36.457745] option 2-1:1.3: GSM modem (1-port) converter detected [  
> 36.465709] usb 2-1: GSM modem (1-port) converter now attached to ttyUSB3
> 
> Does anyone have any suggestions as to what could be the problem with
> runtime pm?