[PATCH u-boot-marvell 5/9] arm: mvebu: a38x: serdes: Don't set PCIe Common Clock Configuration

[Marek Behún]

From: Pali Rohár <pali at kernel.org>

Enabling Common Clock Configuration bit in PCIe Root Port Link Control
Register should not be done unconditionally. It is enabled by operating
system as part of ASPM. Also after enabling Common Clock Configuration it
is required to do more work, like retraining link. Some cards may be broken
due to this incomplete Common Clock Configuration and some cards are broken
and do not support ASPM at all.

Remove this incomplete code for Common Clock Configuration. It really
should not be done in SerDes code as it is not related to SerDes, but to
PCIe subsystem.

Signed-off-by: Pali Rohár <pali at kernel.org>
Reviewed-by: Marek Behún <marek.behun at nic.cz>
---
 .../mach-mvebu/serdes/a38x/high_speed_env_spec.c  | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c b/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
index a712fa8994..824f4d3e3d 100644
--- a/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
+++ b/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
@@ -1737,21 +1737,6 @@ int serdes_power_up_ctrl(u32 serdes_num, int serdes_power_up,
 				reg_data |= (is_pex_by1 ? 1 : 4) << 4;
 				reg_write(PEX0_RP_PCIE_CFG_OFFSET +
 					  PCI_EXP_LNKCAP, reg_data);
-
-				/*
-				 * Set Common Clock Configuration to indicates
-				 * that both devices on the link use a
-				 * distributed common reference clock.
-				 */
-				reg_data = reg_read(PEX_CFG_DIRECT_ACCESS(
-						     pex_idx,
-						     PEX_LINK_CTRL_STAT_REG));
-				reg_data &= ~0x40;
-				reg_data |= 0x40;
-				reg_write(PEX_CFG_DIRECT_ACCESS(
-					   pex_idx,
-					   PEX_LINK_CTRL_STAT_REG),
-					  reg_data);
 			}
 
 			CHECK_STATUS(mv_seq_exec(serdes_num, PEX_POWER_UP_SEQ));
-- 
2.32.0