The fixed_phy_get_gpiod function() returns NULL, it doesn't return error
pointers, using NULL checking to fix this.i
Fixes: 5468e82f70 ("net: phy: fixed-phy: Drop GPIO from fixed_phy_add()")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20211224021500.10362-1-linmq006@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Recently, a patch has been submitted to "fix" the refcounting for a DT
node in of_mdiobus_link_mdiodev(). This is not a leaked refcount. The
refcount is passed to the new device.
Sadly, coccicheck identifies this location as a leaked refcount, which
means we're likely to keep getting patches to "fix" this. However,
fixing this will cause breakage. Add a comment to state that the lack
of of_node_put() here is intentional.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
On mv88e6xxx 1G/2.5G PCS, the SerDes register 4.2001.2 has the following
description:
This register bit indicates when link was lost since the last
read. For the current link status, read this register
back-to-back.
Thus to get current link state, we need to read the register twice.
But doing that in the link change interrupt handler would lead to
potentially ignoring link down events, which we really want to avoid.
Thus this needs to be solved in phylink's resolve, by retriggering
another resolve in the event when PCS reports link down and previous
link was up, and by re-reading PCS state if the previous link was down.
The wrong value is read when phylink requests change from sgmii to
2500base-x mode, and link won't come up. This fixes the bug.
Fixes: 9525ae8395 ("phylink: add phylink infrastructure")
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On PHY state change the phylink_resolve() function can read stale
information from the MAC and report incorrect link speed and duplex to
the kernel message log.
Example with a Marvell 88X3310 PHY connected to a SerDes port on Marvell
88E6393X switch:
- PHY driver triggers state change due to PHY interface mode being
changed from 10gbase-r to 2500base-x due to copper change in speed
from 10Gbps to 2.5Gbps, but the PHY itself either hasn't yet changed
its interface to the host, or the interrupt about loss of SerDes link
hadn't arrived yet (there can be a delay of several milliseconds for
this), so we still think that the 10gbase-r mode is up
- phylink_resolve()
- phylink_mac_pcs_get_state()
- this fills in speed=10g link=up
- interface mode is updated to 2500base-x but speed is left at 10Gbps
- phylink_major_config()
- interface is changed to 2500base-x
- phylink_link_up()
- mv88e6xxx_mac_link_up()
- .port_set_speed_duplex()
- speed is set to 10Gbps
- reports "Link is Up - 10Gbps/Full" to dmesg
Afterwards when the interrupt finally arrives for mv88e6xxx, another
resolve is forced in which we get the correct speed from
phylink_mac_pcs_get_state(), but since the interface is not being
changed anymore, we don't call phylink_major_config() but only
phylink_mac_config(), which does not set speed/duplex anymore.
To fix this, we need to force the link down and trigger another resolve
on PHY interface change event.
Fixes: 9525ae8395 ("phylink: add phylink infrastructure")
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As reported by Zhang there's a small issue if in forced mode the duplex
mode changes with the link staying up [0]. In this case the MAC isn't
notified about the change.
The proposed patch relies on the phylib state machine and ignores the
fact that there are drivers that uses phylib but not the phylib state
machine. So let's don't change the behavior for such drivers and fix
it w/o re-adding state PHY_FORCING for the case that phylib state
machine is used.
[0] https://lore.kernel.org/netdev/a5c26ffd-4ee4-a5e6-4103-873208ce0dc5@huawei.com/T/
Fixes: 2bd229df5e ("net: phy: remove state PHY_FORCING")
Reported-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Tested-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/7b8b9456-a93f-abbc-1dc5-a2c2542f932c@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a function to initialize phy rgmii delay according to phydev->interface.
Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20211101162119.29275-1-yuiko.oshino@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mvneta does not support asymetric pause modes, and it flags this by the
lack of AsymPause in the supported field. When setting pause modes, we
check that pause->rx_pause == pause->tx_pause, but only when pause
autoneg is enabled. When pause autoneg is disabled, we still allow
pause->rx_pause != pause->tx_pause, which is incorrect when the MAC
does not support asymetric pause, and causes mvneta to issue a warning.
Fix this by removing the test for pause->autoneg, so we always check
that pause->rx_pause == pause->tx_pause for network devices that do not
support AsymPause.
Fixes: 9525ae8395 ("phylink: add phylink infrastructure")
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a basic cable test (diagnostic) support for lan87xx phy.
Tested with LAN8770 for connected/open/short wires using ethtool.
Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the following coccicheck warning:
./drivers/net/phy/at803x.c:493:5-10: WARNING: Unsigned expression
compared with zero: value < 0.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Fixes: 7beecaf7d5 ("net: phy: at803x: improve the WOL feature")
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/1635325191-101815-1-git-send-email-jiapeng.chong@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fixed warning: Function parameter or member 'enable' not
described in 'genphy_c45_fast_retrain'
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20211026102957.17100-1-luoj@codeaurora.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If the network device supplies a supported interface bitmap, we can use
that during phylink's validation to simplify MAC drivers in two ways by
using the supported_interfaces bitmap to:
1. reject unsupported interfaces before calling into the MAC driver.
2. generate the set of all supported link modes across all supported
interfaces (used mainly for SFP, but also some 10G PHYs.)
Suggested-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a race condition where the PHY state machine can change
members of the phydev structure at the same time userspace requests a
change via ethtool. To prevent this, have phy_ethtool_ksettings_set
take the PHY lock.
Fixes: 2d55173e71 ("phy: add generic function to support ksetting support")
Reported-by: Walter Stoll <Walter.Stoll@duagon.com>
Suggested-by: Walter Stoll <Walter.Stoll@duagon.com>
Tested-by: Walter Stoll <Walter.Stoll@duagon.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Split phy_start_aneg into a wrapper which takes the PHY lock, and a
helper doing the real work. This will be needed when
phy_ethtook_ksettings_set takes the lock.
Fixes: 2d55173e71 ("phy: add generic function to support ksetting support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows it to make use of a helper which assume the PHY is already
locked.
Fixes: 2d55173e71 ("phy: add generic function to support ksetting support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The PHY structure should be locked while copying information out if
it, otherwise there is no guarantee of self consistency. Without the
lock the PHY state machine could be updating the structure.
Fixes: 2d55173e71 ("phy: add generic function to support ksetting support")
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
To perform CDT of qca8081 phy:
1. disable hibernation.
2. force phy working in MDI mode.
3. force phy working in 1000BASE-T mode.
4. configure the related thresholds.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
1. The master/slave seed needs to be updated when the link can't
be created.
2. The case where two qca8081 PHYs are connected each other and
master/slave seed is generated as the same value also needs
to be considered, so adding this code change into read_status
instead of link_change_notify.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
qca8081 phy is a single port phy, configure
phy the lower seed value to make it linked as slave
mode easier.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the qca8081 phy driver config_init function, which includes:
1. Enable fast restrain.
2. Add 802.3az configurations.
3. Initialize ADC threshold as 100mv.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add generic fast retrain auto-negotiation function for C45 PHYs.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reuse at803x phy driver config_aneg excepting
adding 2500M auto-negotiation.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reuse the at803x phy driver get_features excepting
adding 2500M capability.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
1. Separate the function at803x_read_specific_status from
the at803x_read_status, since it can be reused by the
read_status of qca8081 phy driver excepting adding the
2500M speed.
2. Add the qca8081 read_status function qca808x_read_status.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
qca8081 is a single port ethernet phy chip that supports
10/100/1000/2500 Mbps mode.
Add the basic phy driver features, and reuse the at803x
phy driver functions.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use GENMASK() for the current speed value.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The wol feature is controlled by the MMD3.8012 bit5,
need to set this bit when the wol function is enabled.
The reg18 bit0 is for enabling WOL interrupt, when wol
occurs, the wol interrupt status reg19 bit0 is set to 1.
Call phy_trigger_machine if there are any other interrupt
pending in the function set_wol.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert at803x_set_wol to use phy_modify.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace AT803X_DEVICE_ADDR with MDIO_MMD_PCS defined in mdio.h.
Signed-off-by: Luo Jie <luoj@codeaurora.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
netdev->dev_addr will become a const soon(ish),
constify the local variables referring to it.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
7712 is a 16nm process SoC with a 10/100 integrated Ethernet PHY,
utilize the recently defined 16nm EPHY macro to configure that PHY.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This refactors the phylink pcs helper functions to use mdiobus_* instead
of mdiodev_*.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some Micrel KSZ8041NL PHY chips exhibit continuous RX errors after using
the power down mode bit (0.11). If the PHY is taken out of power down
mode in a certain temperature range, the PHY enters a weird state which
leads to continuously reporting RX errors. In that state, the MAC is not
able to receive or send any Ethernet frames and the activity LED is
constantly blinking. Since Linux is using the suspend callback when the
interface is taken down, ending up in that state can easily happen
during a normal startup.
Micrel confirmed the issue in errata DS80000700A [*], caused by abnormal
clock recovery when using power down mode. Even the latest revision (A4,
Revision ID 0x1513) seems to suffer that problem, and according to the
errata is not going to be fixed.
Remove the suspend/resume callback to avoid using the power down mode
completely.
[*] https://ww1.microchip.com/downloads/en/DeviceDoc/80000700A.pdf
Fixes: 1a5465f5d6 ("phy/micrel: Add suspend/resume support to Micrel PHYs")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The auto-negotiation state in the PCS as set by
phylink_mii_c22_pcs_config was previously always enabled when the
driver is configured for in-band autonegotiation, even if
autonegotiation was disabled on the interface with ethtool. Update the
code to set the BMCR_ANENABLE bit based on the interface's
autonegotiation enabled state.
Update phylink_mii_c22_pcs_get_state to not check
autonegotiation-related fields when autonegotiation is disabled.
Update phylink_mac_pcs_get_state to initialize the state based on the
interface's configured speed, duplex and pause parameters rather than
to unknown when autonegotiation is disabled, before calling the
driver's pcs_get_state functions, as they are not likely to provide
meaningful data for these fields when autonegotiation is disabled. In
this case the driver is really just filling in the link state field.
Note that in cases where there is a downstream PHY connected, such as
with SGMII and a copper PHY, the configuration set by ethtool is
handled by phy_ethtool_ksettings_set and not propagated to the PCS.
This is correct since SGMII or 1000Base-X autonegotiation with the PCS
should normally still be used even if the copper side has disabled it.
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit ea269a6f72 ("net: phylink: Update SFP selected interface on
advertising changes") added a better solution to selecting the
interface mode for SFPs using the advertisement mask. This method will
work for mvneta and mvpp2 when selecting between 2500base-X and
1000base-X without needing to use the basex helper, or indicate that
we support both 1000base-X and 2500base-X when in either of these two
interface modes.
Hence, we need to eliminate the validation prior to selecting the
interface, otherwise when we clean up mvneta's validation function, we
will end up locking to 2500base-X as we validate with an interface mode
of PHY_INERFACE_MODE_2500BASEX.
The supported mask will already have been reduced down to the union of
support for the SFP and MAC already, so we can be confident that the
advertisement mask is already appropriately restricted. We only need to
select the appropriate interface, and then revalidate with the new
interface mode.
We get rid of the check for pl->sfp_port too, this is meaningless here
as it doesn't get cleared when a module is removed, so it doesn't
indicate if a module is present. Just rely on pl->sfp_bus.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The RTL8365MB-VC ethernet switch controller has 4 internal PHYs for its
user-facing ports. All that is needed is to let the PHY driver core
pick up the IRQ made available by the switch driver.
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
PHY driver dp83867 has rich supports for OF-platform to fine-tune the PHY
chip during phy configuration. However, for non-OF platform, certain PHY
tunable parameters such as IO impedance and RX & TX internal delays are
critical and should be initialized to its default during PHY driver probe.
Tested-by: Clement <clement@intel.com>
Signed-off-by: Lay, Kuan Loon <kuan.loon.lay@intel.com>
Co-developed-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Tested-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://lore.kernel.org/r/20211013065941.2124858-1-boon.leong.ong@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
It seems reasonable to fine-tune only some of the skew values when using
one of the rgmii-*id PHY modes, and even when all skew values are
specified, using the correct ID PHY mode makes sense for documentation
purposes. Such a configuration also appears in the binding docs in
Documentation/devicetree/bindings/net/micrel-ksz90x1.txt, so the driver
should not warn about it.
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Link: https://lore.kernel.org/r/20211012103402.21438-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tools/testing/selftests/net/ioam6.sh
7b1700e009 ("selftests: net: modify IOAM tests for undef bits")
bf77b1400a ("selftests: net: Test for the IOAM encapsulation with IPv6")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This big patch sprinkles const on local variables and
function arguments which may refer to netdev->dev_addr.
Commit 406f42fa0d ("net-next: When a bond have a massive amount
of VLANs...") introduced a rbtree for faster Ethernet address look
up. To maintain netdev->dev_addr in this tree we need to make all
the writes to it got through appropriate helpers.
Some of the changes here are not strictly required - const
is sometimes cast off but pointer is not used for writing.
It seems like it's still better to add the const in case
the code changes later or relevant -W flags get enabled
for the build.
No functional changes.
Link: https://lore.kernel.org/r/20211014142432.449314-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Give a name to known debug regs from Documentation instead of using
unknown hex values.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
From original QCA source code the port was set to prefer master as port
type in 1000BASE-T mode. Apply the same settings also here.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
QCA8327 internal phy require DAC amplitude adjustement set to +6% with
100m speed. Also add additional define to report a change of the same
reg in QCA8337. (different scope it does set 1000m voltage)
Add link_change_notify function to set the proper amplitude adjustement
on PHY_RUNNING state and disable on any other state.
Fixes: b4df02b562 ("net: phy: at803x: add support for qca 8327 A variant internal phy")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
From Documentation phy resume triggers phy reset and restart
auto-negotiation. Add a dedicated function to wait reset to finish as
it was notice a regression where port sometime are not reliable after a
suspend/resume session. The reset wait logic is copied from phy_poll_reset.
Add dedicated suspend function to use genphy_suspend only with QCA8337
phy and set only additional debug settings for QCA8327. With more test
it was reported that QCA8327 doesn't proprely support this mode and
using this cause the unreliability of the switch ports, especially the
malfunction of the port0.
Fixes: 15b9df4ece ("net: phy: at803x: add resume/suspend function to qca83xx phy")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case a PHY device was probed thus in the PHY_READY state, but not
configured and with no network device attached yet, we should not be
trying to shut it down because it has been brought back into reset by
phy_device_reset() towards the end of phy_probe() and anyway we have not
configured the PHY yet.
Fixes: e2f016cf77 ("net: phy: add a shutdown procedure")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Micrel KSZ9131 PHY LED behavior is not correct when configured in
Individual Mode, LED1 (Activity LED) is in the ON state when there is
no-link.
Workaround this by setting bit 9 of register 0x1e after verifying that
the LED configuration is Individual Mode.
This issue is described in KSZ9131RNX Silicon Errata DS80000693B [*]
and according to that it will not be corrected in a future silicon
revision.
[*] https://ww1.microchip.com/downloads/en/DeviceDoc/KSZ9131RNX-Silicon-Errata-and-Data-Sheet-Clarification-80000863B.pdf
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Philippe Schenker <philippe.schenker@toradex.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
PHYLIB device drivers must match by either numerical PHY ID or by their
.match_phy_device method. Matching by DT is not permitted.
Link: https://lore.kernel.org/r/2b1dc053-8c9a-e3e4-b450-eecdfca3fe16@gmail.com
Tested-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Miaoqian Lin