[PATCH 2/4] USB: omap_udc: fix crashes on probe error and module removal

[Aaro Koskinen]

We currently crash if usb_add_gadget_udc_release() fails, since the
udc->done is not initialized until in the remove function. Furthermore, on
module removal the udc data is accessed although the release function
is already triggered by usb_del_gadget_udc() early in the function.
Fix by releasing the data manually.

The patch fixes omap_udc module probe with a failing gadged, and also
allows the removal of omap_udc. Tested by running "modprobe omap_udc;
modprobe -r omap_udc" in a loop.

Signed-off-by: Aaro Koskinen <aaro.koski...@iki.fi>
---
 drivers/usb/gadget/udc/omap_udc.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/gadget/udc/omap_udc.c 
b/drivers/usb/gadget/udc/omap_udc.c
index 1c77218c82af..d98782ec254d 100644
--- a/drivers/usb/gadget/udc/omap_udc.c
+++ b/drivers/usb/gadget/udc/omap_udc.c
@@ -2591,9 +2591,8 @@ omap_ep_setup(char *name, u8 addr, u8 type,
        return buf;
 }
 
-static void omap_udc_release(struct device *dev)
+static void omap_udc_release(void)
 {
-       complete(udc->done);
        kfree(udc);
        udc = NULL;
 }
@@ -2900,16 +2899,14 @@ static int omap_udc_probe(struct platform_device *pdev)
        }
 
        create_proc_file();
-       status = usb_add_gadget_udc_release(&pdev->dev, &udc->gadget,
-                       omap_udc_release);
+       status = usb_add_gadget_udc(&pdev->dev, &udc->gadget);
        if (!status)
                return 0;
 
        remove_proc_file();
 
 cleanup1:
-       kfree(udc);
-       udc = NULL;
+       omap_udc_release();
 
 cleanup0:
        if (!IS_ERR_OR_NULL(xceiv))
@@ -2930,8 +2927,6 @@ static int omap_udc_probe(struct platform_device *pdev)
 
 static int omap_udc_remove(struct platform_device *pdev)
 {
-       DECLARE_COMPLETION_ONSTACK(done);
-
        if (!udc)
                return -ENODEV;
 
@@ -2939,8 +2934,6 @@ static int omap_udc_remove(struct platform_device *pdev)
        if (udc->driver)
                return -EBUSY;
 
-       udc->done = &done;
-
        pullup_disable(udc);
        if (!IS_ERR_OR_NULL(udc->transceiver)) {
                usb_put_phy(udc->transceiver);
@@ -2960,7 +2953,7 @@ static int omap_udc_remove(struct platform_device *pdev)
        release_mem_region(pdev->resource[0].start,
                        pdev->resource[0].end - pdev->resource[0].start + 1);
 
-       wait_for_completion(&done);
+       omap_udc_release();
 
        return 0;
 }
-- 
2.17.0