On Wed, Mar 21, 2012 at 09:34:30PM +0530, Kishon Vijay Abraham I wrote:
> During modprobe of gadget driver, pullup(RUN) is called after udc_start. To
> follow symmetry while removing gadget driver, pullup(STOP) is called before
> udc_stop.
>
> This is needed for aggressive PM where udc_stop disables the module completely.
> With aggressive PM, the module is completely disabled, clocks are cut during
> udc_stop. Calling disconnect after udc_stop necessiates clocks to be enabled
> again.
>
> Cc: Felipe Balbi <balbi@xxxxxx>
> Signed-off-by: Partha Basak <p-basak2@xxxxxx>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
applied, but I changed changelog a bit:
commit 74bb842395d4ffb073d3928dc44a6c0a4fd86908
Author: Kishon Vijay Abraham I <kishon@xxxxxx>
Date: Wed Mar 21 21:34:30 2012 +0530
usb: gadget: udc-core: fix asymmetric calls in remove_driver
During modprobe of gadget driver, pullup is called after
udc_start. In order to make the exit path symmetric when
removing a gadget driver, call pullup before ->udc_stop.
This is needed to avoid issues with PM where udc_stop
disables the module completely (put IP in reset state,
cut functional and interface clocks, and so on), which
prevents us from accessing the IP's address space,
thus creating the possibility of an abort exception
when we try to access IP's address space after clocks
are off.
This affects anyone using the sysfs interface for
device-initiated connect/disconnect.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Partha Basak <p-basak2@xxxxxx>
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
you still need to address Greg's concern about stable rules ;-)
--
balbi
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