diff options
| author | Michael Brown | 2021-06-22 15:48:10 +0200 |
|---|---|---|
| committer | Michael Brown | 2021-06-24 13:36:46 +0200 |
| commit | 5622575c5e4bffb07307f39903bb95caad7d172d (patch) | |
| tree | 3bb74d96b17d6807ecfe4cdd8298fdf3a1149c20 /src/drivers | |
| parent | [cloud] Show ifstat output after a failed boot attempt (diff) | |
| download | ipxe-5622575c5e4bffb07307f39903bb95caad7d172d.tar.gz ipxe-5622575c5e4bffb07307f39903bb95caad7d172d.tar.xz ipxe-5622575c5e4bffb07307f39903bb95caad7d172d.zip | |
[realtek] Work around hardware bug on RTL8211B
The RTL8211B seems to have a bug that prevents the link from coming up
unless the MII_MMD_DATA register is cleared.
The Linux kernel driver applies this workaround (in rtl8211b_resume())
only to the specific RTL8211B PHY model, along with a matching
workaround to set bit 9 of MII_MMD_DATA when suspending the PHY.
Since we have no need to ever suspend the PHY, and since writing a
zero ought to be harmless, we just clear the register unconditionally.
Debugged-by: Nikolay Pertsev <nikolay.p@cos.flag.org>
Tested-by: Nikolay Pertsev <nikolay.p@cos.flag.org>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/drivers')
| -rw-r--r-- | src/drivers/net/realtek.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/src/drivers/net/realtek.c b/src/drivers/net/realtek.c index 0af3416d5..a43efb68b 100644 --- a/src/drivers/net/realtek.c +++ b/src/drivers/net/realtek.c @@ -420,6 +420,16 @@ static int realtek_phy_reset ( struct realtek_nic *rtl ) { */ } + /* Some cards (e.g. RTL8211B) have a hardware errata that + * requires the MII_MMD_DATA register to be cleared before the + * link will come up. + */ + if ( ( rc = mii_write ( &rtl->mii, MII_MMD_DATA, 0 ) ) != 0 ) { + /* Ignore failures, since the register may not be + * present on all PHYs. + */ + } + /* Restart autonegotiation */ if ( ( rc = mii_restart ( &rtl->mii ) ) != 0 ) { DBGC ( rtl, "REALTEK %p could not restart MII: %s\n", |