[PATCH] usb: musb: fix enumeration after resume

Andreas Kemnade
2018-01-27T08:34:03Z

On dm3730 there are enumeration problems after resume.
Investigation led to the cause that the MUSB_POWER_SOFTCONN
bit is not set. If it was set before suspend (because it
was enabled via musb_pullup()), it is set in
musb_restore_context() so the pullup is enabled. But then
musb_start() is called which overwrites MUSB_POWER and
therefore disables MUSB_POWER_SOFTCONN, so no pullup is
enabled and the device is not enumerated.

So let's do a subset of what musb_start() does
in the same way as musb_suspend() does it. Platform-specific
stuff it still called as there might be some phy-related stuff
which needs to be enabled.
Also interrupts are enabled, as it was the original idea
of calling musb_start() in musb_resume() according to
Commit 6fc6f4b87cb3 ("usb: musb: Disable interrupts on suspend,
enable them on resume")

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
drivers/usb/musb/musb_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index ea5013aa69e2..255424aae513 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2709,7 +2709,8 @@ static int musb_resume(struct device *dev)
if ((devctl & mask) != (musb->context.devctl & mask))
musb->port1_status = 0;

- musb_start(musb);
+ musb_enable_interrupts(musb);
+ musb_platform_enable(musb);

spin_lock_irqsave(&musb->lock, flags);
error = musb_run_resume_work(musb);
--
2.11.0