Make error reporting in the driver more verbose. This patch is based on
an earlier work by Teppei Kamijou, but we try to not add any new error
messages to the log in the normal case to avoid confusing the user, and
also add a few more dev_dbg() calls.
Signed-off-by: NTeppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: NShinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
[g.liakhovetski@gmx.de: avoid producing new errors in normal case]
Signed-off-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: NChris Ball <cjb@laptop.org>