| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <04e5c795-c246-44e0-a31c-a4ff01b777f9@t-8ch.de>
Date: Mon, 25 Nov 2024 09:50:54 +0100
From: Thomas Weißschuh <thomas@...ch.de>
To: "Sung-Chi, Li" <lschyi@...omium.org>
Cc: Benson Leung <bleung@...omium.org>,
Guenter Roeck <groeck@...omium.org>, Sebastian Reichel <sre@...nel.org>, Lee Jones <lee@...nel.org>,
Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>, chrome-platform@...ts.linux.dev, linux-pm@...r.kernel.org,
linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH 1/2] power: supply: cros_usbpd-charger: extend as a
thermal of cooling device
On 2024-11-25 10:37:47+0800, Sung-Chi, Li wrote:
> On Fri, Nov 22, 2024 at 11:21:18AM +0100, Thomas Weißschuh wrote:
> > On 2024-11-22 11:47:21+0800, Sung-Chi Li wrote:
> > >
> > > diff --git a/drivers/power/supply/cros_usbpd-charger.c b/drivers/power/supply/cros_usbpd-charger.c
> > > index 47d3f58aa15c..a0451630cdd7 100644
> > > --- a/drivers/power/supply/cros_usbpd-charger.c
> > > +++ b/drivers/power/supply/cros_usbpd-charger.c
> > > @@ -13,6 +13,9 @@
> > > #include <linux/platform_device.h>
> > > #include <linux/power_supply.h>
> > > #include <linux/slab.h>
> > > +#ifdef CONFIG_THERMAL_OF
> >
> > Remove this ifdef. The header is perfectly usable in any case.
> >
> > Actually the CONFIG_THERMAL_OF dependency is not needed at all.
> > It is only necessary for devm_thermal_of_zone_register() but not
> > devm_thermal_of_cooling_device_register() which you are using.
> > I am confused.
> >
> > OTOH you are adding the #cooling-cells OF property which itself seems to
> > be only used by devm_thermal_of_zone_register(), so I'm now even more
> > confused.
> >
> > In general, try to also test the driver configurations
> > !CONFIG_THERMAL_OF and !CONFIG_THERMAL.
> >
>
> Thank you, I removed the ifdef. Yes, it is confusing that
> devm_thermal_of_cooling_device_register() does not depend on CONFIG_THERMAL_OF.
> You can supply NULL to the device_node to
> devm_thermal_of_cooling_device_register(), and if you are going the OF route,
> you then fail at devm_thermal_of_zone_register(), because that call requires the
> supplied device_node to have property '#cooling-cells'.
>
> I would like to split the handling on thermal side to OF route and non-OF route,
> so I would use CONFIG_THERMAL_OF to decide which route to go.
Thanks for the clarifications and thinking about this usecase.
> > > +#include <linux/thermal.h>
> > > +#endif /* CONFIG_THERMAL_OF */
> > >
> > > #define CHARGER_USBPD_DIR_NAME "CROS_USBPD_CHARGER%d"
> > > #define CHARGER_DEDICATED_DIR_NAME "CROS_DEDICATED_CHARGER"
> > > @@ -22,6 +25,7 @@
> > > sizeof(CHARGER_DEDICATED_DIR_NAME))
> > > #define CHARGER_CACHE_UPDATE_DELAY msecs_to_jiffies(500)
> > > #define CHARGER_MANUFACTURER_MODEL_LENGTH 32
> > > +#define CHARGER_COOLING_INTERVALS 10
> > >
> > > #define DRV_NAME "cros-usbpd-charger"
> > >
> > > @@ -76,6 +80,8 @@ static enum power_supply_property cros_usbpd_dedicated_charger_props[] = {
> > > /* Input voltage/current limit in mV/mA. Default to none. */
> > > static u16 input_voltage_limit = EC_POWER_LIMIT_NONE;
> > > static u16 input_current_limit = EC_POWER_LIMIT_NONE;
> > > +/* Cooling level interns of current limit */
> > > +static u16 input_current_cooling_level;
> > >
> > > static bool cros_usbpd_charger_port_is_dedicated(struct port_data *port)
> > > {
> > > @@ -459,13 +465,20 @@ static int cros_usbpd_charger_set_prop(struct power_supply *psy,
> s ap> > break;
> > >
> > > input_current_limit = intval;
> > > - if (input_current_limit == EC_POWER_LIMIT_NONE)
> > > + if (input_current_limit == EC_POWER_LIMIT_NONE) {
> > > dev_info(dev,
> > > "External Current Limit cleared for all ports\n");
> > > - else
> > > - dev_info(dev,
> > > - "External Current Limit set to %dmA for all ports\n",
> > > - input_current_limit);
> > > + input_current_cooling_level = 0;
> > > + } else {
> > > + dev_info(
> > > + dev,
> > > + "External Current Limit set to %dmA for all ports\n",
> > > + input_current_limit);
> > > + input_current_cooling_level =
> > > + input_current_limit *
> > > + CHARGER_COOLING_INTERVALS /
> > > + port->psy_current_max;
> >
> > This seems to be a very spammy driver...
> >
>
> Hmm, I did not add extra logs, just that I add more actions in these branches
> when the current limit is applied, so the clang format tool touches these lines.
>
> I think I can revert the formatting changes, and maybe I can make these logs to
> dev_dbg in a following commit.
This wasn't a real review comment for your patch, only a general
observation. Maybe it's worth to have a dedicated commit trimming down
the dev_info() to dev_dbg() and reducing the spam during probe
(failures).
>
> > > + }
> > > break;
> > > case POWER_SUPPLY_PROP_INPUT_VOLTAGE_LIMIT:
> > > ret = cros_usbpd_charger_set_ext_power_limit(charger,
> > > @@ -525,6 +538,66 @@ static void cros_usbpd_charger_unregister_notifier(void *data)
> > > cros_usbpd_unregister_notify(&charger->notifier);
> > > }
> > >
> > > +#ifdef CONFIG_THERMAL_OF
> > > +static int
> > > +cros_usbpd_charger_get_max_cooling_state(struct thermal_cooling_device *cdev,
> > > + unsigned long *cooling_level)
> > > +{
> > > + *cooling_level = CHARGER_COOLING_INTERVALS;
> > > + return 0;
> > > +}
> > > +
> > > +static int
> > > +cros_usbpd_charger_get_cur_cooling_state(struct thermal_cooling_device *cdev,
> > > + unsigned long *cooling_level)
> > > +{
> > > + *cooling_level = input_current_cooling_level;
> > > + return 0;
> > > +}
> > > +
> > > +static int
> > > +cros_usbpd_charger_set_cur_cooling_state(struct thermal_cooling_device *cdev,
> > > + unsigned long cooling_level)
> > > +{
> > > + struct charger_data *charger = cdev->devdata;
> > > + struct port_data *port;
> > > + int current_limit;
> > > + int idx = -1;
> > > + int ret;
> > > +
> > > + for (int i = 0; i < charger->num_registered_psy; i++) {
> > > + port = charger->ports[i];
> > > + if (port->psy_status == POWER_SUPPLY_STATUS_CHARGING) {
> > > + idx = i;
> > > + break;
> > > + }
> > > + }
> >
> > Why not register one cooling device per charger?
> > It would make things more predictable.
> > I have no experience with the thermal subsystem, so this is just a
> > guess.
> >
>
> The driver has only one power limiting instance, so I treat the whole EC as a
> cooling device. This is also more convenient when crafting the thermal zone
> settings. Maybe we can see how other reviewers think?
Yes, I am don't know much about the thermal subsystem.
> > > + .get_max_state = cros_usbpd_charger_get_max_cooling_state,
> > > + .get_cur_state = cros_usbpd_charger_get_cur_cooling_state,
> > > + .set_cur_state = cros_usbpd_charger_set_cur_cooling_state,
> > > +};
> > > +#endif /* CONFIG_THERMAL_OF */
> > > +
> > > static int cros_usbpd_charger_probe(struct platform_device *pd)
> > > {
> > > struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
> > > @@ -534,6 +607,9 @@ static int cros_usbpd_charger_probe(struct platform_device *pd)
> > > struct charger_data *charger;
> > > struct power_supply *psy;
> > > struct port_data *port;
> > > +#ifdef CONFIG_THERMAL_OF
> > > + struct thermal_cooling_device *cdev;
> > > +#endif /* CONFIG_THERMAL_OF */
> > > int ret = -EINVAL;
> > > int i;
> > >
> > > @@ -674,6 +750,18 @@ static int cros_usbpd_charger_probe(struct platform_device *pd)
> > > goto fail;
> > > }
> > >
> > > +#ifdef CONFIG_THERMAL_OF
> >
> > Avoid ifdef in .c files.
> > Use if (IS_ENABLED(CONFIG_THERMAL_OF)) in the normal code flow.
> > The compiler will optimize away all the unreachable code.
> >
>
> Thank you, applied this approach when using CONFIG_THERMAL_OF.
>
> > > + cdev = devm_thermal_of_cooling_device_register(
> > > + dev, ec_device->dev->of_node, DRV_NAME, charger,
> > > + &cros_usbpd_charger_cooling_ops);
> > > + if (IS_ERR(cdev)) {
> > > + dev_err(dev,
> > > + "Failing register thermal cooling device (err:%pe)\n",
> > > + cdev);
> >
> > dev_err_probe().
> >
> > > + goto fail;
> >
> > Does the call to devm_thermal_of_cooling_device_register() work if there
> > is no OF configuration?
> >
> > > + }
> > > +#endif /* CONFIG_THERMAL_OF */
> > > +
> > > return 0;
> > >
> > > fail:
> > >
> > > --
> > > 2.47.0.371.ga323438b13-goog
> > >
>
> As the thermal functionality is later added to extend this driver, I think you
> are right, it would be better to make this behavior just make warnings, rather
> than directly failing this driver probe. Will use dev_warn_probe, and do not
> goto fail branch for registering it as a cooling device.
Can it also be an info? There should be existing devices in the field
without the OF configuration which will run your mainline driver.
Powered by blists - more mailing lists