[PATCH 3.16 031/294] usb: renesas_usbhs: gadget: disable all eps when the driver stops

From: Ben Hutchings
Date: Mon Nov 06 2017 - 19:19:01 EST


3.16.50-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>

commit b8b9c974afee685789fcbb191b52d1790be3608c upstream.

A gadget driver will not disable eps immediately when ->disconnect()
is called. But, since this driver assumes all eps stop after
the ->disconnect(), unexpected behavior happens (especially in system
suspend).
So, this patch disables all eps in usbhsg_try_stop(). After disabling
eps by renesas_usbhs driver, since some functions will be called by
both a gadget and renesas_usbhs driver, renesas_usbhs driver should
protect uep->pipe. To protect uep->pipe easily, this patch adds a new
lock in struct usbhsg_uep.

Fixes: 2f98382dc ("usb: renesas_usbhs: Add Renesas USBHS Gadget")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/usb/renesas_usbhs/mod_gadget.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)

--- a/drivers/usb/renesas_usbhs/mod_gadget.c
+++ b/drivers/usb/renesas_usbhs/mod_gadget.c
@@ -36,6 +36,7 @@ struct usbhsg_gpriv;
struct usbhsg_uep {
struct usb_ep ep;
struct usbhs_pipe *pipe;
+ spinlock_t lock; /* protect the pipe */

char ep_name[EP_NAME_SIZE];

@@ -608,10 +609,16 @@ usbhsg_ep_enable_end:
static int usbhsg_ep_disable(struct usb_ep *ep)
{
struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
- struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
+ struct usbhs_pipe *pipe;
+ unsigned long flags;
+ int ret = 0;

- if (!pipe)
- return -EINVAL;
+ spin_lock_irqsave(&uep->lock, flags);
+ pipe = usbhsg_uep_to_pipe(uep);
+ if (!pipe) {
+ ret = -EINVAL;
+ goto out;
+ }

usbhsg_pipe_disable(uep);
usbhs_pipe_free(pipe);
@@ -619,6 +626,9 @@ static int usbhsg_ep_disable(struct usb_
uep->pipe->mod_private = NULL;
uep->pipe = NULL;

+out:
+ spin_unlock_irqrestore(&uep->lock, flags);
+
return 0;
}

@@ -668,8 +678,11 @@ static int usbhsg_ep_dequeue(struct usb_
{
struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
struct usbhsg_request *ureq = usbhsg_req_to_ureq(req);
- struct usbhs_pipe *pipe = usbhsg_uep_to_pipe(uep);
+ struct usbhs_pipe *pipe;
+ unsigned long flags;

+ spin_lock_irqsave(&uep->lock, flags);
+ pipe = usbhsg_uep_to_pipe(uep);
if (pipe)
usbhs_pkt_pop(pipe, usbhsg_ureq_to_pkt(ureq));

@@ -678,6 +691,7 @@ static int usbhsg_ep_dequeue(struct usb_
* even if the pipe is NULL.
*/
usbhsg_queue_pop(uep, ureq, -ECONNRESET);
+ spin_unlock_irqrestore(&uep->lock, flags);

return 0;
}
@@ -804,10 +818,10 @@ static int usbhsg_try_stop(struct usbhs_
{
struct usbhsg_gpriv *gpriv = usbhsg_priv_to_gpriv(priv);
struct usbhs_mod *mod = usbhs_mod_get_current(priv);
- struct usbhsg_uep *dcp = usbhsg_gpriv_to_dcp(gpriv);
+ struct usbhsg_uep *uep;
struct device *dev = usbhs_priv_to_dev(priv);
unsigned long flags;
- int ret = 0;
+ int ret = 0, i;

/******************** spin lock ********************/
usbhs_lock(priv, flags);
@@ -839,7 +853,9 @@ static int usbhsg_try_stop(struct usbhs_
usbhs_sys_set_test_mode(priv, 0);
usbhs_sys_function_ctrl(priv, 0);

- usbhsg_ep_disable(&dcp->ep);
+ /* disable all eps */
+ usbhsg_for_each_uep_with_dcp(uep, gpriv, i)
+ usbhsg_ep_disable(&uep->ep);

dev_dbg(dev, "stop gadget\n");

@@ -959,6 +975,7 @@ int usbhs_mod_gadget_probe(struct usbhs_
ret = -ENOMEM;
goto usbhs_mod_gadget_probe_err_gpriv;
}
+ spin_lock_init(&uep->lock);

/*
* CAUTION