From: Stefan Agner stefan@agner.ch
[ Upstream commit 2641b62d2fab52648e34cdc6994b2eacde2d27c1 ]
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: 1a5465f5d6a2 ("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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/micrel.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c index f95bd1b0fb965..0b61d80ea3f8c 100644 --- a/drivers/net/phy/micrel.c +++ b/drivers/net/phy/micrel.c @@ -1040,8 +1040,9 @@ static struct phy_driver ksphy_driver[] = { .get_sset_count = kszphy_get_sset_count, .get_strings = kszphy_get_strings, .get_stats = kszphy_get_stats, - .suspend = genphy_suspend, - .resume = genphy_resume, + /* No suspend/resume callbacks because of errata DS80000700A, + * receiver error following software power down. + */ }, { .phy_id = PHY_ID_KSZ8041RNLI, .phy_id_mask = MICREL_PHY_ID_MASK,