45ad6d87fd
[ Upstream commit 734882a8bf984c2ac8a57d8ac3ee53230bd0bed8 ]
Currently the driver calls pm_runtime_put_autosuspend but without ever
having done a pm_runtime_get, this causes the reference count in the pm
runtime core to become -1. The bad reference count causes the core to
sometimes suspend whilst an active SPI transfer is in progress.
arizona spi0.1: SPI transfer timed out
spi_master spi0: failed to transfer one message from queue
The correct proceedure is to do all the initialisation that requires the
hardware to be powered up before enabling the PM runtime, then enable
the PM runtime having called pm_runtime_set_active to inform it that the
hardware is currently powered up. The core will then power it down at
it's leisure and no explicit pm_runtime_put is required.
Fixes: d36ccd9f7ea4 ("spi: cadence: Runtime pm adaptation")
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.