From 9b808f7f395ae375a26e32046b680cf898dacc21 Mon Sep 17 00:00:00 2001 From: Kendall Willis Date: Mon, 28 Apr 2025 15:53:36 -0500 Subject: [PATCH] firmware: ti_sci: Convert CPU latency constraint from us to ms Fix CPU resume latency constraint units sent to device manager through the TI SCI API. The device manager expects CPU resume latency to be in msecs which is passed in with the TI SCI API [1]. CPU latency constraints are set in userspace using the PM QoS framework which uses usecs as the unit. Since PM QoS uses usecs for units and the device manager expects msecs as the unit, TI SCI needs to convert from usecs to msecs before passing to device manager. [1] https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#tisci-msg-lpm-set-latency-constraint Cc: stable@vger.kernel.org Fixes: a7a15754c7f7 ("firmware: ti_sci: add CPU latency constraint management") Signed-off-by: Kendall Willis Link: https://lore.kernel.org/r/20250428205336.2947118-1-k-willis@ti.com Signed-off-by: Nishanth Menon --- drivers/firmware/ti_sci.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c index 806a975fff22..ae5fd1936ad3 100644 --- a/drivers/firmware/ti_sci.c +++ b/drivers/firmware/ti_sci.c @@ -2,7 +2,7 @@ /* * Texas Instruments System Control Interface Protocol Driver * - * Copyright (C) 2015-2024 Texas Instruments Incorporated - https://www.ti.com/ + * Copyright (C) 2015-2025 Texas Instruments Incorporated - https://www.ti.com/ * Nishanth Menon */ @@ -3670,6 +3670,7 @@ static int __maybe_unused ti_sci_suspend(struct device *dev) struct ti_sci_info *info = dev_get_drvdata(dev); struct device *cpu_dev, *cpu_dev_max = NULL; s32 val, cpu_lat = 0; + u16 cpu_lat_ms; int i, ret; if (info->fw_caps & MSG_FLAG_CAPS_LPM_DM_MANAGED) { @@ -3682,9 +3683,16 @@ static int __maybe_unused ti_sci_suspend(struct device *dev) } } if (cpu_dev_max) { - dev_dbg(cpu_dev_max, "%s: sending max CPU latency=%u\n", __func__, cpu_lat); + /* + * PM QoS latency unit is usecs, device manager uses msecs. + * Convert to msecs and round down for device manager. + */ + cpu_lat_ms = cpu_lat / USEC_PER_MSEC; + dev_dbg(cpu_dev_max, "%s: sending max CPU latency=%u ms\n", __func__, + cpu_lat_ms); ret = ti_sci_cmd_set_latency_constraint(&info->handle, - cpu_lat, TISCI_MSG_CONSTRAINT_SET); + cpu_lat_ms, + TISCI_MSG_CONSTRAINT_SET); if (ret) return ret; } -- 2.25.1