On 10/28/24 12:41 AM, Khoa Hoang wrote:
---- On Sun, 27 Oct 2024 07:44:59 -0700 Marek Vasut wrote ---
On 10/27/24 6:12 AM, Khoa Hoang wrote:
In the original code, the MII_ADVERTISE register is modified while auto-negotiation is still in progress, which causes the PHY to lock up with the ASIX AX88179A.
This patch disables auto-negotiation and resets the PHY before modifying the MII_ADVERTISE register, then restarts auto-negotiation afterward. This prevents the PHY from locking up.
Additionally, both AX88179 and AX88179A variants do not appear to support the ADVERTISE_LPACK (BIT(14)) in the MII_ADVERTISE register, as setting this bit does not seem to have any effect. While I do not have access to the AX88179{,A} datasheet, in most Ethernet PHYs, this bit is reserved as 0, so we should avoid setting it.
Signed-off-by: Khoa Hoang admin@khoahoang.com>
drivers/usb/eth/asix88179.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/eth/asix88179.c b/drivers/usb/eth/asix88179.c index 4bd3b9d1..a856aa2d 100644 --- a/drivers/usb/eth/asix88179.c +++ b/drivers/usb/eth/asix88179.c @@ -344,14 +344,22 @@ static int asix_basic_reset(struct ueth_data *dev, AX_MEDIUM_GIGAMODE | AX_MEDIUM_JUMBO_EN; asix_write_cmd(dev, AX_ACCESS_MAC, AX_MEDIUM_STATUS_MODE, 2, 2, tmp16);
+ /* Disable auto-negotiation and reset the PHY */ + *tmp16 = BMCR_RESET;
Why not use the same trick as u16 adv below here ?
u16 reset = BMCR_RESET; asix_write_cmd(dev, AX_ACCESS_PHY, 0x03, MII_BMCR, 2, &reset);
+ asix_write_cmd(dev, AX_ACCESS_PHY, 0x03, MII_BMCR, 2, tmp16);
- u16 adv = 0;
Sure, I can apply this change. I don’t have a strong preference for one approach over the other.
I noticed a mistake in these lines:
- /* Restart auto-negotiation */
- *tmp16 = BMCR_ANENABLE | BMCR_ANRESTART | BMCR_RESET;
- asix_write_cmd(dev, AX_ACCESS_PHY, 0x03, MII_BMCR, 2, tmp16);
The issue is that I set BMCR_RESET, which would reset the PHY’s settings. This should be changed to:
u16 bmcr = 0; asix_read_cmd(dev, AX_ACCESS_PHY, 0x03, MII_BMCR, 2, &bmcr); bmcr |= BMCR_ANENABLE | BMCR_ANRESTART; asix_write_cmd(dev, AX_ACCESS_PHY, 0x03, MII_BMCR, 2, tmp16);
This avoids resetting the PHY settings while enabling and restarting auto-negotiation correctly. Will test this change and update in next version.
Nice !