misc: rtsx: usb: Ensure mmc child device is active when card is present

misc: rtsx: usb: Ensure mmc child device is active when card is present

When a card is present in the reader, the driver currently defers
autosuspend by returning -EAGAIN during the suspend callback to
trigger USB remote wakeup signaling. However, this does not guarantee
that the mmc child device has been resumed, which may cause issues if
it remains suspended while the card is accessible.
This patch ensures that all child devices, including the mmc host
controller, are explicitly resumed before returning -EAGAIN. This
fixes a corner case introduced by earlier remote wakeup handling,
improving reliability of runtime PM when a card is inserted.

Fixes: 883a87ddf2f1 ("misc: rtsx_usb: Use USB remote wakeup signaling for card insertion detection")
Cc: stable@vger.kernel.org
Signed-off-by: Ricky Wu <ricky_wu@realtek.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20250711140143.2105224-1-ricky_wu@realtek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>