From: Wayne Chang waynec@nvidia.com
commit 4c7f9d2e413dc06a157c4e5dccde84aaf4655eb3 upstream.
When we set the dual-role port to Host mode, we observed the following splat: [ 167.057718] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:229 [ 167.057872] Workqueue: events tegra_xusb_usb_phy_work [ 167.057954] Call trace: [ 167.057962] dump_backtrace+0x0/0x210 [ 167.057996] show_stack+0x30/0x50 [ 167.058020] dump_stack_lvl+0x64/0x84 [ 167.058065] dump_stack+0x14/0x34 [ 167.058100] __might_resched+0x144/0x180 [ 167.058140] __might_sleep+0x64/0xd0 [ 167.058171] slab_pre_alloc_hook.constprop.0+0xa8/0x110 [ 167.058202] __kmalloc_track_caller+0x74/0x2b0 [ 167.058233] kvasprintf+0xa4/0x190 [ 167.058261] kasprintf+0x58/0x90 [ 167.058285] tegra_xusb_find_port_node.isra.0+0x58/0xd0 [ 167.058334] tegra_xusb_find_port+0x38/0xa0 [ 167.058380] tegra_xusb_padctl_get_usb3_companion+0x38/0xd0 [ 167.058430] tegra_xhci_id_notify+0x8c/0x1e0 [ 167.058473] notifier_call_chain+0x88/0x100 [ 167.058506] atomic_notifier_call_chain+0x44/0x70 [ 167.058537] tegra_xusb_usb_phy_work+0x60/0xd0 [ 167.058581] process_one_work+0x1dc/0x4c0 [ 167.058618] worker_thread+0x54/0x410 [ 167.058650] kthread+0x188/0x1b0 [ 167.058672] ret_from_fork+0x10/0x20
The function tegra_xusb_padctl_get_usb3_companion eventually calls tegra_xusb_find_port and this in turn calls kasprintf which might sleep and so cannot be called from an atomic context.
Fix this by moving the call to tegra_xusb_padctl_get_usb3_companion to the tegra_xhci_id_work function where it is really needed.
Fixes: f836e7843036 ("usb: xhci-tegra: Add OTG support") Cc: stable@vger.kernel.org Signed-off-by: Wayne Chang waynec@nvidia.com Signed-off-by: Haotien Hsu haotienh@nvidia.com Link: https://lore.kernel.org/r/20230327095548.1599470-1-haotienh@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/host/xhci-tegra.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/usb/host/xhci-tegra.c +++ b/drivers/usb/host/xhci-tegra.c @@ -1225,6 +1225,9 @@ static void tegra_xhci_id_work(struct wo
mutex_unlock(&tegra->lock);
+ tegra->otg_usb3_port = tegra_xusb_padctl_get_usb3_companion(tegra->padctl, + tegra->otg_usb2_port); + if (tegra->host_mode) { /* switch to host mode */ if (tegra->otg_usb3_port >= 0) { @@ -1339,9 +1342,6 @@ static int tegra_xhci_id_notify(struct n }
tegra->otg_usb2_port = tegra_xusb_get_usb2_port(tegra, usbphy); - tegra->otg_usb3_port = tegra_xusb_padctl_get_usb3_companion( - tegra->padctl, - tegra->otg_usb2_port);
tegra->host_mode = (usbphy->last_event == USB_EVENT_ID) ? true : false;