[PATCH] interconnect: qcom: sdm660: Enable keep_alive and sync_state

From: Fabricio Akio via B4 Relay

Date: Fri Oct 09 2026 - 16:46:09 EST


From: Fabricio Akio <fabricioakio@xxxxxxxxx>

The interconnect core starts every node at INT_MAX and only lowers it in
icc_sync_state(), which this driver never hooks up. Every bus therefore
stays at its maximum rate, in the active and the sleep set.

Hook up icc_sync_state(). Releasing those votes also drops buses that no
driver votes for, so enable keep_alive on the providers with a bus clock,
as QCM2290 does: it keeps a minimum active-set vote and leaves the sleep
set free.

On a Motorola Moto X4 (SDM630) with the screen off, this takes the
battery current from 117 mA to 68 mA.

Fixes: f80a1d414328 ("interconnect: qcom: Add SDM660 interconnect provider driver")
Signed-off-by: Fabricio Akio <fabricioakio@xxxxxxxxx>
---
Konrad Dybcio included the sync_state hook-up for this driver in a 2021
fix of its paths [1], Marijn Suijten posted it alone the same year [2],
and Krzysztof Kozlowski for eight Qualcomm drivers in 2022 [3]. Georgi's
concern then was that buses with no bandwidth user would be turned off
at sync state. keep_alive, added since for that case, keeps a minimum
active-set vote on them; QCM2290 and SM6115 use it on all their buses.

Tested on a Motorola Moto X4 (SDM630), whose board file is not in
mainline yet, on the sdm660-mainline tree, with sdm630.dtsi's
interconnect paths as they are in mainline: all six providers synced;
the eMMC, the SD card and the USB gadget worked, and the phone
suspended and resumed.

[1] https://lore.kernel.org/r/20210728222033.52500-1-konrad.dybcio@xxxxxxxxxxxxxx
[2] https://lore.kernel.org/r/20210904111452.248804-1-marijn.suijten@xxxxxxxxxxxxxx
[3] https://lore.kernel.org/r/20220427145616.523557-1-krzysztof.kozlowski@xxxxxxxxxx
---
drivers/interconnect/qcom/sdm660.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/interconnect/qcom/sdm660.c b/drivers/interconnect/qcom/sdm660.c
index d8c979a12235..82dd0b916e1f 100644
--- a/drivers/interconnect/qcom/sdm660.c
+++ b/drivers/interconnect/qcom/sdm660.c
@@ -1514,6 +1514,7 @@ static const struct qcom_icc_desc sdm660_a2noc = {
.intf_clocks = a2noc_intf_clocks,
.num_intf_clocks = ARRAY_SIZE(a2noc_intf_clocks),
.regmap_cfg = &sdm660_a2noc_regmap_config,
+ .keep_alive = true,
};

static struct qcom_icc_node * const sdm660_bimc_nodes[] = {
@@ -1542,6 +1543,7 @@ static const struct qcom_icc_desc sdm660_bimc = {
.bus_clk_desc = &bimc_clk,
.regmap_cfg = &sdm660_bimc_regmap_config,
.ab_coeff = 153,
+ .keep_alive = true,
};

static struct qcom_icc_node * const sdm660_cnoc_nodes[] = {
@@ -1597,6 +1599,7 @@ static const struct qcom_icc_desc sdm660_cnoc = {
.num_nodes = ARRAY_SIZE(sdm660_cnoc_nodes),
.bus_clk_desc = &bus_2_clk,
.regmap_cfg = &sdm660_cnoc_regmap_config,
+ .keep_alive = true,
};

static struct qcom_icc_node * const sdm660_gnoc_nodes[] = {
@@ -1662,6 +1665,7 @@ static const struct qcom_icc_desc sdm660_mnoc = {
.num_intf_clocks = ARRAY_SIZE(mm_intf_clocks),
.regmap_cfg = &sdm660_mnoc_regmap_config,
.ab_coeff = 153,
+ .keep_alive = true,
};

static struct qcom_icc_node * const sdm660_snoc_nodes[] = {
@@ -1698,6 +1702,7 @@ static const struct qcom_icc_desc sdm660_snoc = {
.num_nodes = ARRAY_SIZE(sdm660_snoc_nodes),
.bus_clk_desc = &bus_1_clk,
.regmap_cfg = &sdm660_snoc_regmap_config,
+ .keep_alive = true,
};

static const struct of_device_id sdm660_noc_of_match[] = {
@@ -1717,6 +1722,7 @@ static struct platform_driver sdm660_noc_driver = {
.driver = {
.name = "qnoc-sdm660",
.of_match_table = sdm660_noc_of_match,
+ .sync_state = icc_sync_state,
},
};
module_platform_driver(sdm660_noc_driver);

---
base-commit: aac26bee2287c88af5be5a5ff96d783b19a28790
change-id: 20261009-sdm660-icc-sync-state-0698d9521f4c

Best regards,
--
Fabricio Akio <fabricioakio@xxxxxxxxx>