arm: mvebu: a38x: serdes: Don't set PCIe Common Clock Configuration

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@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>

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 c089479a9b845a20eca380ace1b86ca21db571be..d2bc3ab25c3ffa08d4a0fea4bef9cb7fa738e842 100644 (file)
--- a/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
+++ b/arch/arm/mach-mvebu/serdes/a38x/high_speed_env_spec.c
@@ -1735,21 +1735,6 @@ 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));