[PATCH AUTOSEL 5.4 17/21] usb: dwc2: Adjust the timing of USB Driver Interrupt Registration in the Crashkernel Scenario

[Sasha Levin]

From: Shawn Shao <shawn.shao@xxxxxxxxxxxxxxx>

[ Upstream commit 4058c39bd176daf11a826802d940d86292a6b02b ]

The issue is that before entering the crash kernel, the DWC USB controller
did not perform operations such as resetting the interrupt mask bits.
After entering the crash kernel,before the USB interrupt handler
registration was completed while loading the DWC USB driver,an GINTSTS_SOF
interrupt was received.This triggered the misroute_irq process within the
GIC handling framework,ultimately leading to the misrouting of the
interrupt,causing it to be handled by the wrong interrupt handler
and resulting in the issue.

Summary:In a scenario where the kernel triggers a panic and enters
the crash kernel,it is necessary to ensure that the interrupt mask
bit is not enabled before the interrupt registration is complete.
If an interrupt reaches the CPU at this moment,it will certainly
not be handled correctly,especially in cases where this interrupt
is reported frequently.

Please refer to the Crashkernel dmesg information as follows
(the message on line 3 was added before devm_request_irq is
called by the dwc2_driver_probe function):
[    5.866837][    T1] dwc2 JMIC0010:01: supply vusb_d not found, using dummy regulator
[    5.874588][    T1] dwc2 JMIC0010:01: supply vusb_a not found, using dummy regulator
[    5.882335][    T1] dwc2 JMIC0010:01: before devm_request_irq  irq: [71], gintmsk[0xf300080e], gintsts[0x04200009]
[    5.892686][    C0] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-jmnd1.2_RC #18
[    5.900327][    C0] Hardware name: CMSS HyperCard4-25G/HyperCard4-25G, BIOS 1.6.4 Jul  8 2024
[    5.908836][    C0] Call trace:
[    5.911965][    C0]  dump_backtrace+0x0/0x1f0
[    5.916308][    C0]  show_stack+0x20/0x30
[    5.920304][    C0]  dump_stack+0xd8/0x140
[    5.924387][    C0]  pcie_xxx_handler+0x3c/0x1d8
[    5.930121][    C0]  __handle_irq_event_percpu+0x64/0x1e0
[    5.935506][    C0]  handle_irq_event+0x80/0x1d0
[    5.940109][    C0]  try_one_irq+0x138/0x174
[    5.944365][    C0]  misrouted_irq+0x134/0x140
[    5.948795][    C0]  note_interrupt+0x1d0/0x30c
[    5.953311][    C0]  handle_irq_event+0x13c/0x1d0
[    5.958001][    C0]  handle_fasteoi_irq+0xd4/0x260
[    5.962779][    C0]  __handle_domain_irq+0x88/0xf0
[    5.967555][    C0]  gic_handle_irq+0x9c/0x2f0
[    5.971985][    C0]  el1_irq+0xb8/0x140
[    5.975807][    C0]  __setup_irq+0x3dc/0x7cc
[    5.980064][    C0]  request_threaded_irq+0xf4/0x1b4
[    5.985015][    C0]  devm_request_threaded_irq+0x80/0x100
[    5.990400][    C0]  dwc2_driver_probe+0x1b8/0x6b0
[    5.995178][    C0]  platform_drv_probe+0x5c/0xb0
[    5.999868][    C0]  really_probe+0xf8/0x51c
[    6.004125][    C0]  driver_probe_device+0xfc/0x170
[    6.008989][    C0]  device_driver_attach+0xc8/0xd0
[    6.013853][    C0]  __driver_attach+0xe8/0x1b0
[    6.018369][    C0]  bus_for_each_dev+0x7c/0xdc
[    6.022886][    C0]  driver_attach+0x2c/0x3c
[    6.027143][    C0]  bus_add_driver+0xdc/0x240
[    6.031573][    C0]  driver_register+0x80/0x13c
[    6.036090][    C0]  __platform_driver_register+0x50/0x5c
[    6.041476][    C0]  dwc2_platform_driver_init+0x24/0x30
[    6.046774][    C0]  do_one_initcall+0x50/0x25c
[    6.051291][    C0]  do_initcall_level+0xe4/0xfc
[    6.055894][    C0]  do_initcalls+0x80/0xa4
[    6.060064][    C0]  kernel_init_freeable+0x198/0x240
[    6.065102][    C0]  kernel_init+0x1c/0x12c

Signed-off-by: Shawn Shao <shawn.shao@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240830031709.134-1-shawn.shao@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/usb/dwc2/platform.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 4f640c0c51b39..717fd0c0bccca 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -407,18 +407,6 @@ static int dwc2_driver_probe(struct platform_device *dev)
 
 	spin_lock_init(&hsotg->lock);
 
-	hsotg->irq = platform_get_irq(dev, 0);
-	if (hsotg->irq < 0)
-		return hsotg->irq;
-
-	dev_dbg(hsotg->dev, "registering common handler for irq%d\n",
-		hsotg->irq);
-	retval = devm_request_irq(hsotg->dev, hsotg->irq,
-				  dwc2_handle_common_intr, IRQF_SHARED,
-				  dev_name(hsotg->dev), hsotg);
-	if (retval)
-		return retval;
-
 	hsotg->vbus_supply = devm_regulator_get_optional(hsotg->dev, "vbus");
 	if (IS_ERR(hsotg->vbus_supply)) {
 		retval = PTR_ERR(hsotg->vbus_supply);
@@ -454,6 +442,20 @@ static int dwc2_driver_probe(struct platform_device *dev)
 	if (retval)
 		goto error;
 
+	hsotg->irq = platform_get_irq(dev, 0);
+	if (hsotg->irq < 0) {
+		retval = hsotg->irq;
+		goto error;
+	}
+
+	dev_dbg(hsotg->dev, "registering common handler for irq%d\n",
+		hsotg->irq);
+	retval = devm_request_irq(hsotg->dev, hsotg->irq,
+				  dwc2_handle_common_intr, IRQF_SHARED,
+				  dev_name(hsotg->dev), hsotg);
+	if (retval)
+		goto error;
+
 	/*
 	 * For OTG cores, set the force mode bits to reflect the value
 	 * of dr_mode. Force mode bits should not be touched at any
-- 
2.43.0