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phy: rockchip: inno-usb2: Fix DEBUG_LOCKS_WARN_ON in chg work

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The following trace can be seen if usb is connecting to
Host while do rockchip_chg_detect_work.

 DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current)
 WARNING: CPU: 6 PID: 512 at kernel/locking/rtmutex-debug.c:47 debug_rt_mutex_unlock+0x58/0x64
 Modules linked in:
 CPU: 6 PID: 512 Comm: kworker/6:3 Not tainted 5.10.226-rt89 #186
 Hardware name: Rockchip RK3588 EVB1 LP4 V10 Board (DT)
 Workqueue: events rockchip_chg_detect_work
 pstate: 60c00089 (nZCv daIf +PAN +UAO -TCO BTYPE=--)
 pc : debug_rt_mutex_unlock+0x58/0x64
 lr : debug_rt_mutex_unlock+0x58/0x64
 ......
 Call trace:
  debug_rt_mutex_unlock+0x58/0x64
  __rt_mutex_unlock+0x48/0xf8
  _mutex_unlock+0xc/0x14
  rockchip_chg_detect_work+0x44c/0x6f0
  process_one_work+0x1bc/0x27c
  worker_thread+0x268/0x488
  kthread+0x170/0x210
  ret_from_fork+0x10/0x18

This issue can cause the preempt-rt Linux kernel to crash.
The reason is that all mutexes in preempt-rt have been replaced
with rt_mutexes. An rt_mutex has a PI (Priority Inversion) feature,
which means that when a high-priority task waits for a lock held
by a low-priority task, the priority of the low-priority task is
elevated. A linked list is established on p->pi_waiters. This
requires that lock/unlock operations be handled by the same task.
If unlock is performed and pi_waiters is released by another task,
the task that holds the lock will encounter an exception when
accessing pi_waiters. When executing rockchip_chg_detect_work,
a schedule_delayed_work operation is performed while holding the
mutex lock, causing the mutex lock to be released by a different
worker task, which triggers a kernel panic.

This patch use kthread_work instead of delayed_work to avoid
long-running chg work affecting other tasks in the system workqueue.
And also avoid chg work to be scheduled while hold a mutex lock.

Signed-off-by: William Wu <william.wu@rock-chips.com>
Change-Id: I1e49a22f002b0dfcf0e04d243d99624d34c9a701
This commit is contained in:
William Wu
2025-07-14 09:56:54 +08:00
parent a54e105da3
commit a78b174c2f
1 changed files with 100 additions and 58 deletions
Download Patch File Download Diff File Expand all files Collapse all files

158
drivers/phy/rockchip/phy-rockchip-inno-usb2.c
View File

@@ -267,10 +267,11 @@ struct rockchip_usb2phy_cfg {
* @otg_mux_irq: IRQ number which multiplex otg-id/otg-bvalid/linestate
* irqs to one irq in otg-port.
* @mutex: for register updating in sm_work.
* @chg_work: charge detect work.
* @bypass_uart_work: usb bypass uart work.
* @otg_sm_work: OTG state machine work.
* @sm_work: HOST state machine work.
* @chg_work: charge detect kthread work.
* @chg_worker: charge detect kthread worker.
* @vbus: vbus regulator supply on few rockchip boards.
* @sw: orientation switch, communicate with TCPM (Type-C Port Manager).
* @port_cfg: port register configuration, assigned by driver data.
@@ -304,9 +305,10 @@ struct rockchip_usb2phy_port {
int otg_mux_irq;
struct mutex mutex;
struct delayed_work bypass_uart_work;
struct delayed_work chg_work;
struct delayed_work otg_sm_work;
struct delayed_work sm_work;
struct kthread_work chg_work;
struct kthread_worker *chg_worker;
struct regulator *vbus;
struct typec_switch_dev *sw;
const struct rockchip_usb2phy_port_cfg *port_cfg;
@@ -1306,7 +1308,7 @@ static void rockchip_usb2phy_otg_sm_work(struct work_struct *work)
switch (rphy->chg_state) {
case USB_CHG_STATE_UNDEFINED:
mutex_unlock(&rport->mutex);
schedule_delayed_work(&rport->chg_work, 0);
kthread_queue_work(rport->chg_worker, &rport->chg_work);
return;
case USB_CHG_STATE_DETECTED:
switch (rphy->chg_type) {
@@ -1472,46 +1474,17 @@ static void rockchip_chg_enable_secondary_det(struct rockchip_usb2phy *rphy,
#define CHG_DCD_MAX_RETRIES 6
#define CHG_PRIMARY_DET_TIME (40 * HZ / 1000)
#define CHG_SECONDARY_DET_TIME (40 * HZ / 1000)
static void rockchip_chg_detect_work(struct work_struct *work)
static void rockchip_run_chg_detect_machine(struct rockchip_usb2phy_port *rport)
{
struct rockchip_usb2phy_port *rport =
container_of(work, struct rockchip_usb2phy_port, chg_work.work);
struct rockchip_usb2phy *rphy = dev_get_drvdata(rport->phy->dev.parent);
struct regmap *base = get_reg_base(rphy);
const struct usb2phy_reg *phy_sus_reg;
bool is_dcd, tmout, vout;
unsigned long delay;
unsigned int mask;
int ret;
dev_dbg(&rport->phy->dev, "chg detection work state = %d\n",
rphy->chg_state);
/*
* The conditions for charger detection:
* 1. Set the PHY in normal mode to keep the UTMI_CLK on.
* 2. Set the utmi_opmode in non-driving mode.
* 3. Set the utmi_xcvrselect to FS speed.
* 4. Set the utmi_termselect to FS speed.
* 5. Enable the DP/DM pulldown resistor.
*/
switch (rphy->chg_state) {
case USB_CHG_STATE_UNDEFINED:
mutex_lock(&rport->mutex);
/* Store the PHY current suspend configuration */
phy_sus_reg = &rport->port_cfg->phy_sus;
ret = regmap_read(base, phy_sus_reg->offset,
&rphy->phy_sus_cfg);
if (ret) {
dev_err(&rport->phy->dev,
"Fail to read phy_sus reg offset 0x%x, ret %d\n",
phy_sus_reg->offset, ret);
mutex_unlock(&rport->mutex);
return;
}
/* Set the PHY in charger detection mode */
property_enable(base, &rphy->phy_cfg->chg_det.chg_mode, true);
/* Start DCD processing stage 1 */
rockchip_chg_enable_dcd(rphy, true);
rphy->chg_state = USB_CHG_STATE_WAIT_FOR_DCD;
@@ -1585,37 +1558,75 @@ static void rockchip_chg_detect_work(struct work_struct *work)
fallthrough;
case USB_CHG_STATE_SECONDARY_DONE:
rphy->chg_state = USB_CHG_STATE_DETECTED;
fallthrough;
case USB_CHG_STATE_DETECTED:
if (rphy->phy_cfg->chg_det.chg_mode.offset !=
rport->port_cfg->phy_sus.offset)
property_enable(base, &rphy->phy_cfg->chg_det.chg_mode, false);
/* Restore the PHY suspend configuration */
phy_sus_reg = &rport->port_cfg->phy_sus;
mask = GENMASK(phy_sus_reg->bitend, phy_sus_reg->bitstart);
ret = regmap_write(base, phy_sus_reg->offset,
(rphy->phy_sus_cfg | (mask << BIT_WRITEABLE_SHIFT)));
if (ret)
dev_err(&rport->phy->dev,
"Fail to set phy_sus reg offset 0x%x, ret %d\n",
phy_sus_reg->offset, ret);
mutex_unlock(&rport->mutex);
rockchip_usb2phy_otg_sm_work(&rport->otg_sm_work.work);
dev_dbg(&rport->phy->dev, "charger = %s\n",
chg_to_string(rphy->chg_type));
return;
default:
rphy->chg_state = USB_CHG_STATE_DETECTED;
rphy->chg_type = POWER_SUPPLY_TYPE_UNKNOWN;
return;
}
if (delay)
msleep(jiffies_to_msecs(delay));
}
static void rockchip_chg_detect_work(struct kthread_work *work)
{
struct rockchip_usb2phy_port *rport =
container_of(work, struct rockchip_usb2phy_port, chg_work);
struct rockchip_usb2phy *rphy = dev_get_drvdata(rport->phy->dev.parent);
struct regmap *base = get_reg_base(rphy);
const struct usb2phy_reg *phy_sus_reg;
unsigned int mask;
int ret;
mutex_lock(&rport->mutex);
/* Store the PHY current suspend configuration */
phy_sus_reg = &rport->port_cfg->phy_sus;
ret = regmap_read(base, phy_sus_reg->offset, &rphy->phy_sus_cfg);
if (ret) {
dev_err(&rport->phy->dev,
"Fail to read phy_sus reg offset 0x%x, ret %d\n",
phy_sus_reg->offset, ret);
mutex_unlock(&rport->mutex);
return;
}
/*
* Hold the mutex lock during the whole charger
* detection stage, and release it after detect
* the charger type.
/* Set the PHY in charger detection mode.
* The conditions for charger detection:
* 1. Set the PHY in normal mode to keep the UTMI_CLK on.
* 2. Set the utmi_opmode in non-driving mode.
* 3. Set the utmi_xcvrselect to FS speed.
* 4. Set the utmi_termselect to FS speed.
* 5. Enable the DP/DM pulldown resistor.
*/
schedule_delayed_work(&rport->chg_work, delay);
property_enable(base, &rphy->phy_cfg->chg_det.chg_mode, true);
do {
rockchip_run_chg_detect_machine(rport);
} while (rphy->chg_state != USB_CHG_STATE_UNDEFINED &&
rphy->chg_state != USB_CHG_STATE_DETECTED);
dev_info(&rport->phy->dev, "charger = %s\n", chg_to_string(rphy->chg_type));
/* Disable charger detection mode */
if (rphy->phy_cfg->chg_det.chg_mode.offset != rport->port_cfg->phy_sus.offset)
property_enable(base, &rphy->phy_cfg->chg_det.chg_mode, false);
/* Restore the PHY suspend configuration */
phy_sus_reg = &rport->port_cfg->phy_sus;
mask = GENMASK(phy_sus_reg->bitend, phy_sus_reg->bitstart);
ret = regmap_write(base, phy_sus_reg->offset,
(rphy->phy_sus_cfg | (mask << BIT_WRITEABLE_SHIFT)));
if (ret)
dev_err(&rport->phy->dev,
"Fail to set phy_sus reg offset 0x%x, ret %d\n",
phy_sus_reg->offset, ret);
mutex_unlock(&rport->mutex);
if (rphy->chg_state == USB_CHG_STATE_DETECTED)
rockchip_usb2phy_otg_sm_work(&rport->otg_sm_work.work);
}
/*
@@ -2382,7 +2393,6 @@ static int rockchip_usb2phy_otg_port_init(struct rockchip_usb2phy *rphy,
INIT_DELAYED_WORK(&rport->bypass_uart_work,
rockchip_usb_bypass_uart_work);
INIT_DELAYED_WORK(&rport->chg_work, rockchip_chg_detect_work);
INIT_DELAYED_WORK(&rport->otg_sm_work, rockchip_usb2phy_otg_sm_work);
if (!IS_ERR(rphy->edev)) {
@@ -2396,6 +2406,12 @@ static int rockchip_usb2phy_otg_port_init(struct rockchip_usb2phy *rphy,
}
}
rport->chg_worker = kthread_create_worker(0, "usbchg-worker-%d",
rport->phy->id);
if (IS_ERR(rport->chg_worker))
return PTR_ERR(rport->chg_worker);
kthread_init_work(&rport->chg_work, rockchip_chg_detect_work);
out:
/*
* Let us put phy-port into suspend mode here for saving power
@@ -2626,6 +2642,31 @@ disable_clks:
return ret;
}
static int rockchip_usb2phy_remove(struct platform_device *pdev)
{
struct rockchip_usb2phy *rphy = platform_get_drvdata(pdev);
struct rockchip_usb2phy_port *rport;
unsigned int index;
for (index = 0; index < rphy->phy_cfg->num_ports; index++) {
rport = &rphy->ports[index];
if (!rport->phy)
continue;
if (rport->port_id == USB2PHY_PORT_HOST) {
cancel_delayed_work_sync(&rport->sm_work);
} else if (rport->port_id == USB2PHY_PORT_OTG) {
if (rport->chg_worker)
kthread_destroy_worker(rport->chg_worker);
if (rport->otg_sm_work.work.func)
cancel_delayed_work_sync(&rport->otg_sm_work);
}
}
return 0;
}
static int __maybe_unused
rockchip_usb2phy_low_power_enable(struct rockchip_usb2phy *rphy,
struct rockchip_usb2phy_port *rport,
@@ -4802,6 +4843,7 @@ MODULE_DEVICE_TABLE(of, rockchip_usb2phy_dt_match);
static struct platform_driver rockchip_usb2phy_driver = {
.probe = rockchip_usb2phy_probe,
.remove = rockchip_usb2phy_remove,
.driver = {
.name = "rockchip-usb2phy",
.pm = ROCKCHIP_USB2PHY_DEV_PM,