Re: [PATCH 09/19] atmodem: work around CGREG issues in UBlox Toby L2

[Denis Kenzior <denkenz@gmail.com>]

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Hi Dragos,

On 03/09/2016 09:44 AM, Dragos Tatulea wrote:
> Don't use CGREG for network notifications. It will return
> 4 both when registered in LTE and in unknown state.
>
> For the CGREG? query, interpret 4 as registered.
> ---
>   drivers/atmodem/gprs.c | 24 +++++++++++++++++++++---
>   1 file changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/atmodem/gprs.c b/drivers/atmodem/gprs.c
> index 4505477..0b4bce8 100644
> --- a/drivers/atmodem/gprs.c
> +++ b/drivers/atmodem/gprs.c
> @@ -101,6 +101,17 @@ static void at_cgreg_cb(gboolean ok, GAtResult *result, gpointer user_data)
>   		return;
>   	}
>
> +	if (gd->vendor == OFONO_VENDOR_UBLOX_TOBY_L2 && status == 4) {
> +		/*
> +		 * UBX-13002752-R33 says:
> +		 * If the module is registered to E-UTRAN the <stat> parameter is 4.
> +		 * So this means we are actually registered.
> +		 * It could also mean that state is unknown, but if we are
> +		 * here we know we already registered.
> +		 */
> +		 status = 1;
> +	}
> +

Does ublox support AT+UREG? ?  Perhaps that would be easier than making 
this hack.  The core polls gprs_driver->attached_status in various 
cases, so assuming that 4==1 here seems unsafe.

>   	cb(&error, status, cbd->data);
>   }
>
> @@ -342,16 +353,23 @@ static void gprs_initialized(gboolean ok, GAtResult *result, gpointer user_data)
>   	struct gprs_data *gd = ofono_gprs_get_data(gprs);
>
>   	g_at_chat_register(gd->chat, "+CGEV:", cgev_notify, FALSE, gprs, NULL);
> -	g_at_chat_register(gd->chat, "+CGREG:", cgreg_notify,
> -						FALSE, gprs, NULL);
> +
> +	/*
> +	 * You really don't want to get CGREG notifications on Toby l2.
> +	 * It sends 4 when BOTH for unknown state and for registered in LTE.
> +	 * +UREG usage is recommended by them.
> +	 */
> +	if (gd->vendor != OFONO_VENDOR_UBLOX_TOBY_L2)
> +		g_at_chat_register(gd->chat, "+CGREG:", cgreg_notify,
> +							FALSE, gprs, NULL);
>
>   	switch (gd->vendor) {
>   	case OFONO_VENDOR_HUAWEI:
>   		g_at_chat_register(gd->chat, "^MODE:", huawei_mode_notify,
>   						FALSE, gprs, NULL);
>   		break;
> -	case OFONO_VENDOR_UBLOX:
>   	case OFONO_VENDOR_UBLOX_TOBY_L2:
> +	case OFONO_VENDOR_UBLOX:
>   		g_at_chat_register(gd->chat, "+UREG:", ublox_ureg_notify,
>   						FALSE, gprs, NULL);
>   		g_at_chat_send(gd->chat, "AT+UREG=1", none_prefix,
>

Regards,
-Denis