Red Hat Bugzilla – Bug 509585
[RHEL 5.3] problems changing coalesce settings <=12us on bnx2x
Last modified: 2010-11-09 07:24:19 EST
Description of problem:
Setting to anything <= 12 causes all network traffic to 'disappear',
cannot ping, telnet, etc.
Bringing the interface down, then setting to > 12 will correct the issue.
Version-Release number of selected component (if applicable):
RHEL 5.3 x86_64 (-155 from dzickus tested as well)
static int bnx2x_set_coalesce(struct net_device *dev,
struct ethtool_coalesce *coal)
struct bnx2x *bp = netdev_priv(dev);
bp->rx_ticks = (u16) coal->rx_coalesce_usecs;
if (bp->rx_ticks > 3000)
bp->rx_ticks = 3000;
static void bnx2x_update_coalesce(struct bnx2x *bp)
REG_WR8(bp, BAR_USTRORM_INTMEM +
Usually a code like that 'rx_ticks/12' means the board register accepts
multiples of 12, so you can configure 0us, 12us, 24us, 36us, 48us, 60us...
Upstream does that too.
Broadcom driver does that too.
I looks like a hardware limitation, though I don't have any detailed
board specification to make sure.
However, it should not stop working because someone tried to configure
a value less or equal 12us.
Created attachment 350651 [details]
patch fixing rx coalesce
I've received a feedback from Broadcom on this. The FW supports coalescing
in 12us granularity, and so value of less then 12 should be interpreted as
Could you give a try on the attached patch?
I missed/forgot about that bug. It is duplicate (already solved).
*** This bug has been marked as a duplicate of bug 522600 ***