As detailed in the thread titled "viafb PLL/clock tweaking causes XO-1.5
instability," enabling or disabling the IGA1/IGA2 clocks causes occasional
stability problems during suspend/resume cycles on this platform.
This is rather odd, as the documentation suggests that clocks have two
states (on/off) and the default (stable) configuration is configured to
enable the clock only when it is needed. However, explicitly enabling *or*
disabling the clock triggers this system instability, suggesting that there
is a 3rd state at play here.
Leaving the clock enable/disable registers alone solves this problem.
This fixes spurious reboots during suspend/resume behaviour introduced by
commit b692a63a.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: stable@vger.kernel.org
This patch adds support for enabling and configuring the engine on
VIAs IGPs. This is the main clock used for everything but pixel
output.
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
This patch introduces dummy functions to execute when we don't know
what we should do (due to missing documentation). They do nothing
but print a nice message in the log explaining the situation.
To trigger this message initial power management support is
activated which might save a bit energy by disabling PLL and clock
if no device is configured to use them.
Note: The message is only shown for the oldest IGPs CLE266 and K400
as for the other platforms there are reasonable assumptions
how it does (hopefully) work.
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
This patch is a huge move operation with some rename and introduces
an interface to still use the functions. This should be a step in
the right direction to reuse the code whenever possible but cleanly
separate code that differs on different platform and keeping the
complexity as low as possible.
pll_config was renamed to via_pll_config to keep the naming scheme.
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
