diff options
| author | Michael Brown <mcb30@ipxe.org> | 2021-06-22 14:48:10 +0100 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2021-06-24 12:36:46 +0100 |
| commit | 5622575c5e4bffb07307f39903bb95caad7d172d (patch) | |
| tree | 3bb74d96b17d6807ecfe4cdd8298fdf3a1149c20 | |
| parent | 0688114ea63fee21c39d94cc8df9e2a5003ac283 (diff) | |
| download | ipxe-realtek_hack.zip ipxe-realtek_hack.tar.gz ipxe-realtek_hack.tar.bz2 | |
[realtek] Work around hardware bug on RTL8211Brealtek_hack
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>
| -rw-r--r-- | src/drivers/net/realtek.c | 10 | ||||
| -rw-r--r-- | src/include/mii.h | 2 |
2 files changed, 12 insertions, 0 deletions
diff --git a/src/drivers/net/realtek.c b/src/drivers/net/realtek.c index 0af3416..a43efb6 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", diff --git a/src/include/mii.h b/src/include/mii.h index e2afef8..515ba22 100644 --- a/src/include/mii.h +++ b/src/include/mii.h @@ -23,6 +23,8 @@ FILE_LICENCE ( GPL2_ONLY ); #define MII_EXPANSION 0x06 /* Expansion register */ #define MII_CTRL1000 0x09 /* 1000BASE-T control */ #define MII_STAT1000 0x0a /* 1000BASE-T status */ +#define MII_MMD_CTRL 0x0d /* MMD Access Control Register */ +#define MII_MMD_DATA 0x0e /* MMD Access Data Register */ #define MII_ESTATUS 0x0f /* Extended Status */ #define MII_DCOUNTER 0x12 /* Disconnect counter */ #define MII_FCSCOUNTER 0x13 /* False carrier counter */ |