[PATCH v3 2/2] usb: gadget: f_mass_storage: Disable eps during disconnect

From: Wesley Cheng
Date: Wed Oct 27 2021 - 16:10:29 EST


When receiving a disconnect event from the UDC, the mass storage
function driver currently runs the handle_exception() routine
asynchronously. For UDCs that support runtime PM, there is a
possibility the UDC is already suspended by the time the
do_set_interface() is executed. This can lead to HW register access
while the UDC is already suspended.

Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
---
drivers/usb/gadget/function/f_mass_storage.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/usb/gadget/function/f_mass_storage.c b/drivers/usb/gadget/function/f_mass_storage.c
index 3cabf76..7524396 100644
--- a/drivers/usb/gadget/function/f_mass_storage.c
+++ b/drivers/usb/gadget/function/f_mass_storage.c
@@ -2342,6 +2342,16 @@ static void fsg_disable(struct usb_function *f)
{
struct fsg_dev *fsg = fsg_from_func(f);

+ /* Disable the endpoints */
+ if (fsg->bulk_in_enabled) {
+ usb_ep_disable(fsg->bulk_in);
+ fsg->bulk_in_enabled = 0;
+ }
+ if (fsg->bulk_out_enabled) {
+ usb_ep_disable(fsg->bulk_out);
+ fsg->bulk_out_enabled = 0;
+ }
+
__raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, NULL);
}