When gadget registration fails, one should not call usb_del_gadget_udc().
Ensure this by setting gadget->udc to NULL. Also in case of a failure
there is no need to disable low-level hardware, so return immiedetly
instead of jumping to error_init label.
This fixes the following kernel NULL ptr dereference on gadget failure
(can be easily triggered with g_mass_storage without any module
parameters):
dwc2
12480000.hsotg: dwc2_check_params: Invalid parameter besl=1
dwc2
12480000.hsotg: dwc2_check_params: Invalid parameter g_np_tx_fifo_size=1024
dwc2
12480000.hsotg: EPs: 16, dedicated fifos, 7808 entries in SPRAM
Mass Storage Function, version: 2009/09/11
LUN: removable file: (no medium)
no file given for LUN0
g_mass_storage
12480000.hsotg: failed to start g_mass_storage: -22
8<--- cut here ---
Unable to handle kernel NULL pointer dereference at virtual address
00000104
pgd = (ptrval)
[
00000104] *pgd=
00000000
Internal error: Oops: 805 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.8.0-rc5 #3133
Hardware name: Samsung Exynos (Flattened Device Tree)
Workqueue: events deferred_probe_work_func
PC is at usb_del_gadget_udc+0x38/0xc4
LR is at __mutex_lock+0x31c/0xb18
...
Process kworker/0:1 (pid: 12, stack limit = 0x(ptrval))
Stack: (0xef121db0 to 0xef122000)
...
[<
c076bf3c>] (usb_del_gadget_udc) from [<
c0726bec>] (dwc2_hsotg_remove+0x10/0x20)
[<
c0726bec>] (dwc2_hsotg_remove) from [<
c0711208>] (dwc2_driver_probe+0x57c/0x69c)
[<
c0711208>] (dwc2_driver_probe) from [<
c06247c0>] (platform_drv_probe+0x6c/0xa4)
[<
c06247c0>] (platform_drv_probe) from [<
c0621df4>] (really_probe+0x200/0x48c)
[<
c0621df4>] (really_probe) from [<
c06221e8>] (driver_probe_device+0x78/0x1fc)
[<
c06221e8>] (driver_probe_device) from [<
c061fcd4>] (bus_for_each_drv+0x74/0xb8)
[<
c061fcd4>] (bus_for_each_drv) from [<
c0621b54>] (__device_attach+0xd4/0x16c)
[<
c0621b54>] (__device_attach) from [<
c0620c98>] (bus_probe_device+0x88/0x90)
[<
c0620c98>] (bus_probe_device) from [<
c06211b0>] (deferred_probe_work_func+0x3c/0xd0)
[<
c06211b0>] (deferred_probe_work_func) from [<
c0149280>] (process_one_work+0x234/0x7dc)
[<
c0149280>] (process_one_work) from [<
c014986c>] (worker_thread+0x44/0x51c)
[<
c014986c>] (worker_thread) from [<
c0150b1c>] (kthread+0x158/0x1a0)
[<
c0150b1c>] (kthread) from [<
c0100114>] (ret_from_fork+0x14/0x20)
Exception stack(0xef121fb0 to 0xef121ff8)
...
---[ end trace
9724c2fc7cc9c982 ]---
While fixing this also fix the double call to dwc2_lowlevel_hw_disable()
if dr_mode is set to USB_DR_MODE_PERIPHERAL. In such case low-level
hardware is already disabled before calling usb_add_gadget_udc(). That
function correctly preserves low-level hardware state, there is no need
for the second unconditional dwc2_lowlevel_hw_disable() call.
Fixes:
207324a321a8 ("usb: dwc2: Postponed gadget registration to the udc class driver")
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>