broadband-modem-mbim: consistently handle custom data classes

Consistently interpret the modem's reported custom data class when
loading current mode, supported mode, supported capabilities,
setting current mode, and current access technology.

Normalize the data class to include any custom data class immediately
after reading it from any MBIM message. De-normalize it when sending
back to the modem when setting current modes so the modem receives
MBIM_DATA_CLASS_CUSTOM for the custom mode.

Fixes: https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/937

Signed-off-by: Dan Williams <dan@ioncontrol.co>

1 files changed, 70 insertions, 15 deletions

diff --git a/src/mm-modem-helpers-mbim.c b/src/mm-modem-helpers-mbim.c
index 49d38531..aef31866 100644
--- a/src/mm-modem-helpers-mbim.c
+++ b/src/mm-modem-helpers-mbim.c
@@ -25,10 +25,77 @@
 
 /*****************************************************************************/
 
+typedef struct {
+    const gchar         *custom_class;
+    const MbimDataClass  primary_data_class;
+    const MbimDataClass  secondary_data_class;
+} CustomDataClass;
+
+static const CustomDataClass custom_data_classes[] = {
+    /* "5GSA/TDS": Quectel RM502Q */
+    { "5GSA",    MBIM_DATA_CLASS_5G_SA,                        MBIM_DATA_CLASS_NONE },
+    /* "5G/TDS": Telit FN990, Quectel RM502Q, Gosuncn GM800
+     * "5G":     Dell Snapdragon X55/Foxconn T99W175
+     */
+    { "5G",    MBIM_DATA_CLASS_5G_NSA,                        MBIM_DATA_CLASS_5G_SA },
+    /* "HSPA+": Dell DW5821e/Foxconn T77W968, Huawei EM820W */
+    { "HSPA+", MBIM_DATA_CLASS_HSDPA | MBIM_DATA_CLASS_HSUPA, MBIM_DATA_CLASS_NONE },
+};
+
+MbimDataClass
+mm_mbim_data_class_from_custom_caps (MbimDataClass  orig_data_class,
+                                     const gchar   *custom_data_class)
+{
+    guint i;
+
+    if (orig_data_class & MBIM_DATA_CLASS_CUSTOM) {
+        for (i = 0; i < G_N_ELEMENTS (custom_data_classes); i++) {
+            if (strstr (custom_data_class, custom_data_classes[i].custom_class)) {
+                /* If the original data class already includes the primary custom
+                 * class add the secondary instead. Devices sometimes report a variant
+                 * of the custom class depending on MBIMex version.
+                 *
+                 * For example, Foxconn X55 supports SA but reports "...,lte,custom"
+                 * with MBIMex1 and "...,lte,5g-nsa,custom" with MBIMex2. Fix that
+                 * up with the highest level we can be sure the device supports.
+                 */
+                if (orig_data_class & custom_data_classes[i].primary_data_class)
+                    return custom_data_classes[i].secondary_data_class;
+                else
+                    return custom_data_classes[i].primary_data_class;
+            }
+        }
+    }
+    return MBIM_DATA_CLASS_NONE;
+}
+
+MbimDataClass
+mm_modem_mbim_normalize_data_class_mask (MbimDataClass orig_data_class,
+                                         MbimDataClass custom_data_class)
+{
+    if (orig_data_class & MBIM_DATA_CLASS_CUSTOM) {
+        orig_data_class |= custom_data_class;
+        orig_data_class &= ~MBIM_DATA_CLASS_CUSTOM;
+    }
+    return orig_data_class;
+}
+
+MbimDataClass
+mm_modem_mbim_denormalize_data_class_mask (MbimDataClass orig_data_class,
+                                           MbimDataClass custom_data_class)
+{
+    if (orig_data_class & custom_data_class) {
+        orig_data_class &= ~custom_data_class;
+        orig_data_class |= MBIM_DATA_CLASS_CUSTOM;
+    }
+    return orig_data_class;
+}
+
+/*****************************************************************************/
+
 MMModemCapability
 mm_modem_capability_from_mbim_device_caps (MbimCellularClass  caps_cellular_class,
-                                           MbimDataClass      caps_data_class,
-                                           const gchar       *caps_custom_data_class)
+                                           MbimDataClass      caps_data_class)
 {
     MMModemCapability mask = 0;
 
@@ -43,12 +110,6 @@ mm_modem_capability_from_mbim_device_caps (MbimCellularClass  caps_cellular_clas
     if (caps_data_class & MBIM_DATA_CLASS_LTE)
         mask |= MM_MODEM_CAPABILITY_LTE;
 
-    /* e.g. Gosuncn GM800 reports MBIM custom data class "5G/TDS" */
-    if ((caps_data_class & MBIM_DATA_CLASS_CUSTOM) && caps_custom_data_class) {
-        if (strstr (caps_custom_data_class, "5G"))
-            mask |= MM_MODEM_CAPABILITY_5GNR;
-    }
-
     /* Support for devices with Microsoft extensions */
     if (caps_data_class & (MBIM_DATA_CLASS_5G_NSA | MBIM_DATA_CLASS_5G_SA))
         mask |= MM_MODEM_CAPABILITY_5GNR;
@@ -148,8 +209,7 @@ mm_modem_3gpp_packet_service_state_from_mbim_packet_service_state (MbimPacketSer
 /*****************************************************************************/
 
 MMModemMode
-mm_modem_mode_from_mbim_data_class (MbimDataClass  data_class,
-                                    const gchar   *caps_custom_data_class)
+mm_modem_mode_from_mbim_data_class (MbimDataClass  data_class)
 {
     MMModemMode mask = MM_MODEM_MODE_NONE;
 
@@ -166,11 +226,6 @@ mm_modem_mode_from_mbim_data_class (MbimDataClass  data_class,
     if (data_class & (MBIM_DATA_CLASS_5G_NSA |
                       MBIM_DATA_CLASS_5G_SA))
         mask |= MM_MODEM_MODE_5G;
-    /* Some modems (e.g. Telit FN990) reports MBIM custom data class "5G/TDS" */
-    if ((data_class & MBIM_DATA_CLASS_CUSTOM) && caps_custom_data_class) {
-        if (strstr (caps_custom_data_class, "5G"))
-            mask |= MM_MODEM_MODE_5G;
-    }
 
     /* 3GPP2... */
     if (data_class & MBIM_DATA_CLASS_1XRTT)