Hi Daniel,
On 09/02/2014 03:00 PM, Daniel Thompson wrote:
The architectures where this peripheral exists (ARM and SH) have expensive implementations of writel(), reliant on spin locks and explicit L2 cache management. These architectures provide a cheaper writel_relaxed() which is much better suited to peripherals that do not perform DMA. The situation with readl()/readl_relaxed()is similar although less acute.
This driver does not use DMA and will be more power efficient and more robust (due to absense of spin locks during console I/O) if it uses the relaxed variants.
This change means the driver is no longer portable and therefore no longer suitable for compile testing.
Signed-off-by: Daniel Thompson daniel.thompson@linaro.org Cc: Srinivas Kandagatla srinivas.kandagatla@gmail.com Cc: Maxime Coquelin maxime.coquelin@st.com Cc: Patrice Chotard patrice.chotard@st.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Jiri Slaby jslaby@suse.cz Cc: kernel@stlinux.com Cc: linux-serial@vger.kernel.org
drivers/tty/serial/Kconfig | 2 +- drivers/tty/serial/st-asc.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
You can add my: Acked-by: Maxime Coquelin maxime.coquelin@st.com
thanks! Maxime