As can be seen from [1]:
"...the different behavior between iMX6Q PCIe and iMX7D PCIe maybe caused
by the different controller version.
Regarding to the DOC description, the DIRECT_SPEED_CHANGE should be
cleared after the speed change from GEN1 to GEN2. Unfortunately, when
GEN1 device is used, the behavior is not documented.
So, IC design guys run the simulation and find out the following
behaviors:
1. DIRECT_SPEED_CHANGE will be cleared in 7D after speed change
from GEN1 to GEN2. This matches doc’s description
2. set MAX link speed(PCIE_CAP_TARGET_LINK_SPEED=0x01) as GEN1 and
re-run the simulation, DIRECT_SPEED_CHANGE will not be cleared;
remain as 1, this matches your result, but function test is
passed, so this bit should not affect the normal PCIe function."
imx6_pcie_wait_for_speed_change() will report false failures for Gen1 ->
Gen1 speed transition, so avoid doing that check and just rely on
imx6_pcie_wait_for_link() only.
[1] https://community.nxp.com/message/867943
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Cc: yurovsky@gmail.com
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Dong Aisheng <dongas86@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
e6dcd87fff