The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8d396bb0a5b62b326f6be7594d8bd46b088296bd Mon Sep 17 00:00:00 2001

From: Jack Pham jackp@codeaurora.org Date: Sat, 29 May 2021 12:29:32 -0700 Subject: [PATCH] usb: dwc3: debugfs: Add and remove endpoint dirs dynamically

The DWC3 DebugFS directory and files are currently created once during probe. This includes creation of subdirectories for each of the gadget's endpoints. This works fine for peripheral-only controllers, as dwc3_core_init_mode() calls dwc3_gadget_init() just prior to calling dwc3_debugfs_init().

However, for dual-role controllers, dwc3_core_init_mode() will instead call dwc3_drd_init() which is problematic in a few ways. First, the initial state must be determined, then dwc3_set_mode() will have to schedule drd_work and by then dwc3_debugfs_init() could have already been invoked. Even if the initial mode is peripheral, dwc3_gadget_init() happens after the DebugFS files are created, and worse so if the initial state is host and the controller switches to peripheral much later. And secondly, even if the gadget endpoints' debug entries were successfully created, if the controller exits peripheral mode, its dwc3_eps are freed so the debug files would now hold stale references.

So it is best if the DebugFS endpoint entries are created and removed dynamically at the same time the underlying dwc3_eps are. Do this by calling dwc3_debugfs_create_endpoint_dir() as each endpoint is created, and conversely remove the DebugFS entry when the endpoint is freed.

Fixes: 41ce1456e1db ("usb: dwc3: core: make dwc3_set_mode() work properly") Cc: stable stable@vger.kernel.org Reviewed-by: Peter Chen peter.chen@kernel.org Signed-off-by: Jack Pham jackp@codeaurora.org Link: https://lore.kernel.org/r/20210529192932.22912-1-jackp@codeaurora.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/usb/dwc3/debug.h b/drivers/usb/dwc3/debug.h index d0ac89c5b317..d223c54115f4 100644 --- a/drivers/usb/dwc3/debug.h +++ b/drivers/usb/dwc3/debug.h @@ -413,9 +413,12 @@ static inline const char *dwc3_gadget_generic_cmd_status_string(int status)

#ifdef CONFIG_DEBUG_FS +extern void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep); extern void dwc3_debugfs_init(struct dwc3 *d); extern void dwc3_debugfs_exit(struct dwc3 *d); #else +static inline void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep) +{ } static inline void dwc3_debugfs_init(struct dwc3 *d) { } static inline void dwc3_debugfs_exit(struct dwc3 *d) diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c index 7146ee2ac057..5dbbe53269d3 100644 --- a/drivers/usb/dwc3/debugfs.c +++ b/drivers/usb/dwc3/debugfs.c @@ -886,30 +886,14 @@ static void dwc3_debugfs_create_endpoint_files(struct dwc3_ep *dep, } }

-static void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep, - struct dentry *parent) +void dwc3_debugfs_create_endpoint_dir(struct dwc3_ep *dep) { struct dentry *dir;

- dir = debugfs_create_dir(dep->name, parent); + dir = debugfs_create_dir(dep->name, dep->dwc->root); dwc3_debugfs_create_endpoint_files(dep, dir); }

-static void dwc3_debugfs_create_endpoint_dirs(struct dwc3 *dwc, - struct dentry *parent) -{ - int i; - - for (i = 0; i < dwc->num_eps; i++) { - struct dwc3_ep *dep = dwc->eps[i]; - - if (!dep) - continue; - - dwc3_debugfs_create_endpoint_dir(dep, parent); - } -} - void dwc3_debugfs_init(struct dwc3 *dwc) { struct dentry *root; @@ -940,7 +924,6 @@ void dwc3_debugfs_init(struct dwc3 *dwc) &dwc3_testmode_fops); debugfs_create_file("link_state", 0644, root, dwc, &dwc3_link_state_fops); - dwc3_debugfs_create_endpoint_dirs(dwc, root); } }

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 88270eee8a48..f14c2aa83759 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2753,6 +2753,8 @@ static int dwc3_gadget_init_endpoint(struct dwc3 *dwc, u8 epnum) INIT_LIST_HEAD(&dep->started_list); INIT_LIST_HEAD(&dep->cancelled_list);

+ dwc3_debugfs_create_endpoint_dir(dep); + return 0; }

@@ -2796,6 +2798,7 @@ static void dwc3_gadget_free_endpoints(struct dwc3 *dwc) list_del(&dep->endpoint.ep_list); }

+ debugfs_remove_recursive(debugfs_lookup(dep->name, dwc->root)); kfree(dep); } }