From patchwork Tue Jan 22 08:30:35 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [net] r8169: remove the obsolete and incorrect AMD workaround Date: Mon, 21 Jan 2013 22:30:35 -0000 From: =?utf-8?q?Timo_Ter=C3=A4s?= X-Patchwork-Id: 214467 Message-Id: <1358843435-24719-1-git-send-email-timo.teras@iki.fi> To: Francois Romieu , netdev@vger.kernel.org Cc: =?UTF-8?q?Timo=20Ter=C3=A4s?= This was introduced in commit 6dccd16 "r8169: merge with version 6.001.00 of Realtek's r8169 driver". I did not find the version 6.001.00 online, but in 6.002.00 or any later r8169 from Realtek this hunk is no longer present. Also commit 05af214 "r8169: fix Ethernet Hangup for RTL8110SC rev d" claims to have fixed this issue otherwise. The magic compare mask of 0xfffe000 is dubious as it masks parts of the Reserved part, and parts of the VLAN tag. But this does not make much sense as the VLAN tag parts are perfectly valid there. In matter of fact this seems to be triggered with any VLAN tagged packet as RxVlanTag bit is matched. I would suspect 0xfffe0000 was intended to test reserved part only. Finally, this hunk is evil as it can cause more packets to be handled than what was NAPI quota causing net/core/dev.c: net_rx_action(): WARN_ON_ONCE(work > weight) to trigger, and mess up the NAPI state causing device to hang. As result, any system using VLANs and having high receive traffic (so that NAPI poll budget limits rtl_rx) would result in device hang. Signed-off-by: Timo Teräs Acked-by: Francois Romieu --- I decided to suggest just removal without the suggested WARN_ON_ONCE. This is because the test is incorrect as explained above, and not present anywhere else either. Oh yeah, and I'm feeling brave today ;) If acceptable, this should go to -stable too. The hunk was introduced in v2.6.23-rc1 and the alternate fix went in to v2.6.32-rc6. drivers/net/ethernet/realtek/r8169.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index ed96f30..c28bc31 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -6111,13 +6111,6 @@ process_pkt: tp->rx_stats.bytes += pkt_size; u64_stats_update_end(&tp->rx_stats.syncp); } - - /* Work around for AMD plateform. */ - if ((desc->opts2 & cpu_to_le32(0xfffe000)) && - (tp->mac_version == RTL_GIGA_MAC_VER_05)) { - desc->opts2 = 0; - cur_rx++; - } } count = cur_rx - tp->cur_rx;