This is a note to let you know that I've just added the patch titled usb: gadget: udc: renesas_usb3: lock for PN_ registers access to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-gadget-udc-renesas_usb3-lock-for-pn_-registers-access.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 940f538a100c84c6e72813e4ac88bd1753a86945 Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Date: Wed, 26 Apr 2017 20:50:09 +0900 Subject: usb: gadget: udc: renesas_usb3: lock for PN_ registers access From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> commit 940f538a100c84c6e72813e4ac88bd1753a86945 upstream. This controller disallows to change the PIPE until reading/writing a packet finishes. However. the previous code is not enough to hold the lock in some functions. So, this patch fixes it. Fixes: 746bfe63bba3 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx> Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/udc/renesas_usb3.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -1401,7 +1401,13 @@ static void usb3_request_done_pipen(stru struct renesas_usb3_request *usb3_req, int status) { - usb3_pn_stop(usb3); + unsigned long flags; + + spin_lock_irqsave(&usb3->lock, flags); + if (usb3_pn_change(usb3, usb3_ep->num)) + usb3_pn_stop(usb3); + spin_unlock_irqrestore(&usb3->lock, flags); + usb3_disable_pipe_irq(usb3, usb3_ep->num); usb3_request_done(usb3_ep, usb3_req, status); @@ -1430,30 +1436,46 @@ static void usb3_irq_epc_pipen_bfrdy(str { struct renesas_usb3_ep *usb3_ep = usb3_get_ep(usb3, num); struct renesas_usb3_request *usb3_req = usb3_get_request(usb3_ep); + bool done = false; if (!usb3_req) return; + spin_lock(&usb3->lock); + if (usb3_pn_change(usb3, num)) + goto out; + if (usb3_ep->dir_in) { /* Do not stop the IN pipe here to detect LSTTR interrupt */ if (!usb3_write_pipe(usb3_ep, usb3_req, USB3_PN_WRITE)) usb3_clear_bit(usb3, PN_INT_BFRDY, USB3_PN_INT_ENA); } else { if (!usb3_read_pipe(usb3_ep, usb3_req, USB3_PN_READ)) - usb3_request_done_pipen(usb3, usb3_ep, usb3_req, 0); + done = true; } + +out: + /* need to unlock because usb3_request_done_pipen() locks it */ + spin_unlock(&usb3->lock); + + if (done) + usb3_request_done_pipen(usb3, usb3_ep, usb3_req, 0); } static void usb3_irq_epc_pipen(struct renesas_usb3 *usb3, int num) { u32 pn_int_sta; - if (usb3_pn_change(usb3, num) < 0) + spin_lock(&usb3->lock); + if (usb3_pn_change(usb3, num) < 0) { + spin_unlock(&usb3->lock); return; + } pn_int_sta = usb3_read(usb3, USB3_PN_INT_STA); pn_int_sta &= usb3_read(usb3, USB3_PN_INT_ENA); usb3_write(usb3, pn_int_sta, USB3_PN_INT_STA); + spin_unlock(&usb3->lock); if (pn_int_sta & PN_INT_LSTTR) usb3_irq_epc_pipen_lsttr(usb3, num); if (pn_int_sta & PN_INT_BFRDY) Patches currently in stable-queue which might be from yoshihiro.shimoda.uh@xxxxxxxxxxx are queue-4.9/usb-gadget-udc-renesas_usb3-fix-deadlock-by-spinlock.patch queue-4.9/usb-gadget-udc-renesas_usb3-fix-pm_runtime-functions-calling.patch queue-4.9/usb-gadget-udc-renesas_usb3-lock-for-pn_-registers-access.patch