dm: core: Avoid partially removing devices

At present if device_remove() decides that the device should not actually
be removed, it still calls the uclass pre_remove() method and powers the
device down.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c
index 35b625e..bc99ef0 100644 (file)
--- a/drivers/core/device-remove.c
+++ b/drivers/core/device-remove.c
@@ -8,6 +8,8 @@
  * Pavel Herrmann <morpheus.ibis@gmail.com>
  */
 
+#define LOG_CATEGORY   LOGC_DM
+
 #include <common.h>
 #include <errno.h>
 #include <log.h>
@@ -54,7 +56,7 @@ int device_chld_remove(struct udevice *dev, struct driver *drv,
                        continue;
 
                ret = device_remove(pos, flags);
-               if (ret)
+               if (ret && ret != -EKEYREJECTED)
                        return ret;
        }
 
@@ -149,13 +151,24 @@ void device_free(struct udevice *dev)
        devres_release_probe(dev);
 }
 
-static bool flags_remove(uint flags, uint drv_flags)
+/**
+ * flags_remove() - Figure out whether to remove a device
+ *
+ * @flags: Flags passed to device_remove()
+ * @drv_flags: Driver flags
+ * @return 0 if the device should be removed,
+ * -EKEYREJECTED if @flags includes a flag in DM_REMOVE_ACTIVE_ALL but
+ *     @drv_flags does not (indicates that this device has nothing to do for
+ *     DMA shutdown or OS prepare)
+ */
+static int flags_remove(uint flags, uint drv_flags)
 {
-       if ((flags & DM_REMOVE_NORMAL) ||
-           (flags && (drv_flags & (DM_FLAG_ACTIVE_DMA | DM_FLAG_OS_PREPARE))))
-               return true;
+       if (flags & DM_REMOVE_NORMAL)
+               return 0;
+       if (flags && (drv_flags & DM_REMOVE_ACTIVE_ALL))
+               return 0;
 
-       return false;
+       return -EKEYREJECTED;
 }
 
 int device_remove(struct udevice *dev, uint flags)
@@ -169,22 +182,32 @@ int device_remove(struct udevice *dev, uint flags)
        if (!(dev_get_flags(dev) & DM_FLAG_ACTIVATED))
                return 0;
 
+       /*
+        * If the child returns EKEYREJECTED, continue. It just means that it
+        * didn't match the flags.
+        */
+       ret = device_chld_remove(dev, NULL, flags);
+       if (ret && ret != -EKEYREJECTED)
+               return ret;
+
+       /*
+        * Remove the device if called with the "normal" remove flag set,
+        * or if the remove flag matches any of the drivers remove flags
+        */
        drv = dev->driver;
        assert(drv);
-
-       ret = device_chld_remove(dev, NULL, flags);
-       if (ret)
+       ret = flags_remove(flags, drv->flags);
+       if (ret) {
+               log_debug("%s: When removing: flags=%x, drv->flags=%x, err=%d\n",
+                         dev->name, flags, drv->flags, ret);
                return ret;
+       }
 
        ret = uclass_pre_remove_device(dev);
        if (ret)
                return ret;
 
-       /*
-        * Remove the device if called with the "normal" remove flag set,
-        * or if the remove flag matches any of the drivers remove flags
-        */
-       if (drv->remove && flags_remove(flags, drv->flags)) {
+       if (drv->remove) {
                ret = drv->remove(dev);
                if (ret)
                        goto err_remove;
@@ -204,13 +227,11 @@ int device_remove(struct udevice *dev, uint flags)
            dev != gd->cur_serial_dev)
                dev_power_domain_off(dev);
 
-       if (flags_remove(flags, drv->flags)) {
-               device_free(dev);
+       device_free(dev);
 
-               dev_bic_flags(dev, DM_FLAG_ACTIVATED);
-       }
+       dev_bic_flags(dev, DM_FLAG_ACTIVATED);
 
-       return ret;
+       return 0;
 
 err_remove:
        /* We can't put the children back */

diff --git a/include/dm/device-internal.h b/include/dm/device-internal.h
index 639bbd2..b513b68 100644 (file)
--- a/include/dm/device-internal.h
+++ b/include/dm/device-internal.h
@@ -123,7 +123,8 @@ int device_probe(struct udevice *dev);
  *
  * @dev: Pointer to device to remove
  * @flags: Flags for selective device removal (DM_REMOVE_...)
- * @return 0 if OK, -ve on error (an error here is normally a very bad thing)
+ * @return 0 if OK, -EKEYREJECTED if not removed due to flags, other -ve on
+ *     error (such an error here is normally a very bad thing)
  */
 #if CONFIG_IS_ENABLED(DM_DEVICE_REMOVE)
 int device_remove(struct udevice *dev, uint flags);
@@ -173,6 +174,12 @@ static inline int device_chld_unbind(struct udevice *dev, struct driver *drv)
 
 /**
  * device_chld_remove() - Stop all device's children
+ *
+ * This continues through all children recursively stopping part-way through if
+ * an error occurs. Return values of -EKEYREJECTED are ignored and processing
+ * continues, since they just indicate that the child did not elect to be
+ * removed based on the value of @flags.
+ *
  * @dev:       The device whose children are to be removed
  * @drv:       The targeted driver
  * @flags:     Flag, if this functions is called in the pre-OS stage

diff --git a/test/dm/virtio.c b/test/dm/virtio.c
index ad35598..9a7e658 100644 (file)
--- a/test/dm/virtio.c
+++ b/test/dm/virtio.c
@@ -123,7 +123,9 @@ static int dm_test_virtio_remove(struct unit_test_state *uts)
 
        /* check the device can be successfully removed */
        dev_or_flags(dev, DM_FLAG_ACTIVATED);
-       ut_assertok(device_remove(bus, DM_REMOVE_ACTIVE_ALL));
+       ut_asserteq(-EKEYREJECTED, device_remove(bus, DM_REMOVE_ACTIVE_ALL));
+
+       ut_asserteq(false, device_active(dev));
 
        return 0;
 }