Lantiq: make possible to tweak DSL SRN from UCI

This patch makes possible to tweak the downstream SNR margin on
Lantiq DSL devices.

The UCI parameter 'network.dsl.ds_snr_offset' is used to set the SNR
margin offset. It accepts values in range -50 to +50 in 0.1 dB units.

The SNR margin can thus be modified in range -5.0 to +5.0 dB in 0.1 dB
steps.

Currently this should only affect ADSL (not VDSL). It should be very
easy to make this work also on VDSL lines, but since I couldn't test
on VDSL lines this patch does not do that yet.

I have also a patch for LUCI about this, that I could submit.

Tested on FB3370 (Lantiq VR9) and Telecom Italia ADSL2+ line.

Signed-off-by: Andrea Merello <andrea.merello@gmail.com>

diff --git a/package/network/config/ltq-vdsl-app/files/dsl_control b/package/network/config/ltq-vdsl-app/files/dsl_control
index 5ca1b12eea90cb70c7a6ef89e6f32ab3b8e58a80..c659d50e1b8d2fa5c98a3afc666626b4ba767124 100644 (file)
--- a/package/network/config/ltq-vdsl-app/files/dsl_control
+++ b/package/network/config/ltq-vdsl-app/files/dsl_control
@@ -96,6 +96,22 @@ tone_vdsl_b="0x1" # B43
 tone_adsl_bv="0x81" # B43 + B43c
 tone_vdsl_bv="0x5" # B43 + V43
 
+# create ADSL autoboot script. Used for SNR margin tweak
+autoboot_script() {
+    echo "[WaitForConfiguration]={
+locs 0 $1
+}
+
+[WaitForLinkActivate]={
+}
+
+[WaitForRestart]={
+}
+
+[Common]={
+}" > /tmp/adsl.scr
+}
+
 lowlevel_cfg() {
        echo "# VRX Low Level Configuration File
 #
@@ -166,6 +182,7 @@ start_service() {
        local line_mode
        local mode
        local lowlevel
+       local snr
 
        config_load network
        config_get tone dsl tone
@@ -173,6 +190,7 @@ start_service() {
        config_get firmware dsl firmware
        config_get xfer_mode dsl xfer_mode
        config_get line_mode dsl line_mode
+       config_get snr dsl ds_snr_offset
 
        eval "xtse=\"\${xtse_xdsl_$annex}\""
 
@@ -262,13 +280,20 @@ start_service() {
                lowlevel="-l /tmp/lowlevel.cfg"
        }
 
+       [ -z "${snr}" ] || {
+           # for SNR offset setting
+           autoboot_script "$snr"
+           autoboot="-a /tmp/adsl.scr"
+       }
+
        procd_open_instance
        procd_set_param command /sbin/vdsl_cpe_control_wrapper \
                        -i$xtse \
                        -n /sbin/dsl_notify.sh \
                        -f ${firmware} \
                        $lowlevel \
-                       -M ${mode}
+                       -M ${mode} \
+                       $autoboot
        procd_append_param env "LOAD=$LOAD" "UNLOAD=$UNLOAD"
        procd_close_instance
 }