Now that the upstream code has been getting broader test coverage by our
users we occasionally see issues with USB2 devices plugged in during boot.
Before Linux is running, the USB2 PHY has usually been running in device
mode and it turns out that sometimes host->device or device->host
transitions don't work.
The root cause: If the role inside the USB2 PHY is re-configured when it
has already been powered on or when dwc2 has already enabled the ULPI
interface the new configuration sometimes doesn't take affect until dwc3
is reset again. Fix this rare issue by configuring the role much earlier.
Note that the USB3 PHY does not suffer from this issue and actually
requires dwc3 to be up before the correct role can be configured there.
Reported-by: James Calligeros <jcalligeros99(a)gmail.com>
Reported-by: Janne Grunau <j(a)jannau.net>
Fixes: 0ec946d32ef7 ("usb: dwc3: Add Apple Silicon DWC3 glue layer driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Sven Peter <sven(a)kernel.org>
---
drivers/usb/dwc3/dwc3-apple.c | 48 +++++++++++++++++++++++++++++--------------
1 file changed, 33 insertions(+), 15 deletions(-)
diff --git a/drivers/usb/dwc3/dwc3-apple.c b/drivers/usb/dwc3/dwc3-apple.c
index cc47cad232e397ac4498b09165dfdb5bd215ded7..c2ae8eb21d514e5e493d2927bc12908c308dfe19 100644
--- a/drivers/usb/dwc3/dwc3-apple.c
+++ b/drivers/usb/dwc3/dwc3-apple.c
@@ -218,25 +218,31 @@ static int dwc3_apple_core_init(struct dwc3_apple *appledwc)
return ret;
}
-static void dwc3_apple_phy_set_mode(struct dwc3_apple *appledwc, enum phy_mode mode)
-{
- lockdep_assert_held(&appledwc->lock);
-
- /*
- * This platform requires SUSPHY to be enabled here already in order to properly configure
- * the PHY and switch dwc3's PIPE interface to USB3 PHY.
- */
- dwc3_enable_susphy(&appledwc->dwc, true);
- phy_set_mode(appledwc->dwc.usb2_generic_phy[0], mode);
- phy_set_mode(appledwc->dwc.usb3_generic_phy[0], mode);
-}
-
static int dwc3_apple_init(struct dwc3_apple *appledwc, enum dwc3_apple_state state)
{
int ret, ret_reset;
lockdep_assert_held(&appledwc->lock);
+ /*
+ * The USB2 PHY on this platform must be configured for host or device mode while it is
+ * still powered off and before dwc3 tries to access it. Otherwise, the new configuration
+ * will sometimes only take affect after the *next* time dwc3 is brought up which causes
+ * the connected device to just not work.
+ * The USB3 PHY must be configured later after dwc3 has already been initialized.
+ */
+ switch (state) {
+ case DWC3_APPLE_HOST:
+ phy_set_mode(appledwc->dwc.usb2_generic_phy[0], PHY_MODE_USB_HOST);
+ break;
+ case DWC3_APPLE_DEVICE:
+ phy_set_mode(appledwc->dwc.usb2_generic_phy[0], PHY_MODE_USB_DEVICE);
+ break;
+ default:
+ /* Unreachable unless there's a bug in this driver */
+ return -EINVAL;
+ }
+
ret = reset_control_deassert(appledwc->reset);
if (ret) {
dev_err(appledwc->dev, "Failed to deassert reset, err=%d\n", ret);
@@ -257,7 +263,13 @@ static int dwc3_apple_init(struct dwc3_apple *appledwc, enum dwc3_apple_state st
case DWC3_APPLE_HOST:
appledwc->dwc.dr_mode = USB_DR_MODE_HOST;
dwc3_apple_set_ptrcap(appledwc, DWC3_GCTL_PRTCAP_HOST);
- dwc3_apple_phy_set_mode(appledwc, PHY_MODE_USB_HOST);
+ /*
+ * This platform requires SUSPHY to be enabled here already in order to properly
+ * configure the PHY and switch dwc3's PIPE interface to USB3 PHY. The USB2 PHY
+ * has already been configured to the correct mode earlier.
+ */
+ dwc3_enable_susphy(&appledwc->dwc, true);
+ phy_set_mode(appledwc->dwc.usb3_generic_phy[0], PHY_MODE_USB_HOST);
ret = dwc3_host_init(&appledwc->dwc);
if (ret) {
dev_err(appledwc->dev, "Failed to initialize host, ret=%d\n", ret);
@@ -268,7 +280,13 @@ static int dwc3_apple_init(struct dwc3_apple *appledwc, enum dwc3_apple_state st
case DWC3_APPLE_DEVICE:
appledwc->dwc.dr_mode = USB_DR_MODE_PERIPHERAL;
dwc3_apple_set_ptrcap(appledwc, DWC3_GCTL_PRTCAP_DEVICE);
- dwc3_apple_phy_set_mode(appledwc, PHY_MODE_USB_DEVICE);
+ /*
+ * This platform requires SUSPHY to be enabled here already in order to properly
+ * configure the PHY and switch dwc3's PIPE interface to USB3 PHY. The USB2 PHY
+ * has already been configured to the correct mode earlier.
+ */
+ dwc3_enable_susphy(&appledwc->dwc, true);
+ phy_set_mode(appledwc->dwc.usb3_generic_phy[0], PHY_MODE_USB_DEVICE);
ret = dwc3_gadget_init(&appledwc->dwc);
if (ret) {
dev_err(appledwc->dev, "Failed to initialize gadget, ret=%d\n", ret);
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20260108-dwc3-apple-usb2phy-fix-cf1d26018dd0
Best regards,
--
Sven Peter <sven(a)kernel.org>
Ignore USB role switches if dwc3-apple is already in the desired state.
The USB-C port controller on M2 and M1/M2 Pro/Max/Ultra devices issues
additional interrupts which result in USB role switches to the already
active role.
Ignore these USB role switches to ensure the USB-C port controller and
dwc3-apple are always in a consistent state. This matches the behaviour
in __dwc3_set_mode() in core.c.
Fixes detecting USB 2.0 and 3.x devices on the affected systems. The
reset caused by the additional role switch appears to leave the USB
devices in a state which prevents detection when the phy and dwc3 is
brought back up again.
Fixes: 0ec946d32ef7 ("usb: dwc3: Add Apple Silicon DWC3 glue layer driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Janne Grunau <j(a)jannau.net>
---
drivers/usb/dwc3/dwc3-apple.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/usb/dwc3/dwc3-apple.c b/drivers/usb/dwc3/dwc3-apple.c
index cc47cad232e397ac4498b09165dfdb5bd215ded7..35eadd1fa08049829ba40651a96eb122ed55460f 100644
--- a/drivers/usb/dwc3/dwc3-apple.c
+++ b/drivers/usb/dwc3/dwc3-apple.c
@@ -339,6 +339,22 @@ static int dwc3_usb_role_switch_set(struct usb_role_switch *sw, enum usb_role ro
guard(mutex)(&appledwc->lock);
+ /*
+ * Skip role switches if appledwc is already in the desired state. The
+ * USB-C port controller on M2 and M1/M2 Pro/Max/Ultra devices issues
+ * additional interrupts which results in usb_role_switch_set_role()
+ * calls with the current role.
+ * Ignore those calls here to ensure the USB-C port controller and
+ * appledwc are in a consistent state.
+ * This matches the behaviour in __dwc3_set_mode().
+ * Do no handle USB_ROLE_NONE for DWC3_APPLE_NO_CABLE and
+ * DWC3_APPLE_PROBE_PENDING since that is no-op anyway.
+ */
+ if (appledwc->state == DWC3_APPLE_HOST && role == USB_ROLE_HOST)
+ return 0;
+ if (appledwc->state == DWC3_APPLE_DEVICE && role == USB_ROLE_DEVICE)
+ return 0;
+
/*
* We need to tear all of dwc3 down and re-initialize it every time a cable is
* connected or disconnected or when the mode changes. See the documentation for enum
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20260109-apple-dwc3-role-switch-1b684f73860c
Best regards,
--
Janne Grunau <j(a)jannau.net>
Before this change the LED was added to leds_list before led_init_core()
gets called adding it the list before led_classdev.set_brightness_work gets
initialized.
This leaves a window where led_trigger_register() of a LED's default
trigger will call led_trigger_set() which calls led_set_brightness()
which in turn will end up queueing the *uninitialized*
led_classdev.set_brightness_work.
This race gets hit by the lenovo-thinkpad-t14s EC driver which registers
2 LEDs with a default trigger provided by snd_ctl_led.ko in quick
succession. The first led_classdev_register() causes an async modprobe of
snd_ctl_led to run and that async modprobe manages to exactly hit
the window where the second LED is on the leds_list without led_init_core()
being called for it, resulting in:
------------[ cut here ]------------
WARNING: CPU: 11 PID: 5608 at kernel/workqueue.c:4234 __flush_work+0x344/0x390
Hardware name: LENOVO 21N2S01F0B/21N2S01F0B, BIOS N42ET93W (2.23 ) 09/01/2025
...
Call trace:
__flush_work+0x344/0x390 (P)
flush_work+0x2c/0x50
led_trigger_set+0x1c8/0x340
led_trigger_register+0x17c/0x1c0
led_trigger_register_simple+0x84/0xe8
snd_ctl_led_init+0x40/0xf88 [snd_ctl_led]
do_one_initcall+0x5c/0x318
do_init_module+0x9c/0x2b8
load_module+0x7e0/0x998
Close the race window by moving the adding of the LED to leds_list to
after the led_init_core() call.
Cc: Sebastian Reichel <sre(a)kernel.org>
Cc: stable(a)vger.kernel.org
Signed-off-by: Hans de Goede <johannes.goede(a)oss.qualcomm.com>
---
Note no Fixes tag as this problem has been around for a long long time,
so I could not really find a good commit for the Fixes tag.
---
drivers/leds/led-class.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index f3faf37f9a08..6b9fa060c3a1 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -560,11 +560,6 @@ int led_classdev_register_ext(struct device *parent,
#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
led_cdev->brightness_hw_changed = -1;
#endif
- /* add to the list of leds */
- down_write(&leds_list_lock);
- list_add_tail(&led_cdev->node, &leds_list);
- up_write(&leds_list_lock);
-
if (!led_cdev->max_brightness)
led_cdev->max_brightness = LED_FULL;
@@ -574,6 +569,11 @@ int led_classdev_register_ext(struct device *parent,
led_init_core(led_cdev);
+ /* add to the list of leds */
+ down_write(&leds_list_lock);
+ list_add_tail(&led_cdev->node, &leds_list);
+ up_write(&leds_list_lock);
+
#ifdef CONFIG_LEDS_TRIGGERS
led_trigger_set_default(led_cdev);
#endif
--
2.52.0
In gs_can_open(), the URBs for USB-in transfers are allocated, added to the
parent->rx_submitted anchor and submitted. In the complete callback
gs_usb_receive_bulk_callback(), the URB is processed and resubmitted. In
gs_can_close() the URBs are freed by calling
usb_kill_anchored_urbs(parent->rx_submitted).
However, this does not take into account that the USB framework
unanchors the URB before the close function is called. This means that
once an in-URB has been completed, it is no longer anchored and is
ultimately not released in gs_can_close().
Fix the memory leak by anchoring the URB in the
gs_usb_receive_bulk_callback() to the parent->rx_submitted anchor.
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Cc: stable(a)vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl(a)pengutronix.de>
---
Changes in v2:
- correct "Fixes" tag
- add stable(a)v.k.o on Cc
- Link to v1: https://patch.msgid.link/20251225-gs_usb-fix-memory-leak-v1-1-a7b09e70d01d@…
---
drivers/net/can/usb/gs_usb.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index a0233e550a5a..d093babbc320 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -751,6 +751,8 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
hf, parent->hf_size_rx,
gs_usb_receive_bulk_callback, parent);
+ usb_anchor_urb(urb, &parent->rx_submitted);
+
rc = usb_submit_urb(urb, GFP_ATOMIC);
/* USB failure take down all interfaces */
---
base-commit: 1806d210e5a8f431ad4711766ae4a333d407d972
change-id: 20251225-gs_usb-fix-memory-leak-062c24898cc9
Best regards,
--
Marc Kleine-Budde <mkl(a)pengutronix.de>