Messages in this thread | | | Date | Tue, 6 Dec 2022 09:23:27 +0100 | Subject | Re: [PATCH] net: fec: properly guard irq coalesce setup | From | Rasmus Villemoes <> |
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On 06/12/2022 07.16, Alexander Stein wrote: > Am Montag, 5. Dezember 2022, 21:46:04 CET schrieb Rasmus Villemoes: >> Prior to the Fixes: commit, the initialization code went through the >> same fec_enet_set_coalesce() function as used by ethtool, and that >> function correctly checks whether the current variant has support for >> irq coalescing. >> >> Now that the initialization code instead calls fec_enet_itr_coal_set() >> directly, that call needs to be guarded by a check for the >> FEC_QUIRK_HAS_COALESCE bit. >> >> Fixes: df727d4547de (net: fec: don't reset irq coalesce settings to defaults >> on "ip link up") Reported-by: Greg Ungerer <gregungerer@westnet.com.au> >> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> >> --- >> drivers/net/ethernet/freescale/fec_main.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/freescale/fec_main.c >> b/drivers/net/ethernet/freescale/fec_main.c index >> 2ca2b61b451f..23e1a94b9ce4 100644 >> --- a/drivers/net/ethernet/freescale/fec_main.c >> +++ b/drivers/net/ethernet/freescale/fec_main.c >> @@ -1220,7 +1220,8 @@ fec_restart(struct net_device *ndev) >> writel(0, fep->hwp + FEC_IMASK); >> >> /* Init the interrupt coalescing */ >> - fec_enet_itr_coal_set(ndev); >> + if (fep->quirks & FEC_QUIRK_HAS_COALESCE) >> + fec_enet_itr_coal_set(ndev); >> } >> >> static int fec_enet_ipc_handle_init(struct fec_enet_private *fep) > > I'm wondering if this check should be added to fec_enet_itr_coal_set() > instead. Right now any additional caller has to do it's own check for > FEC_QUIRK_HAS_COALESCE, so why not do check in fec_enet_itr_coal_set?
Yeah, I did consider that (see https://lore.kernel.org/netdev/72eb4e63-10a8-702b-1113-7588fcade9fc@rasmusvillemoes.dk/). But in the end I decided against it, for various small reasons. Primarily my thinking was that while this caller is obviously ok with fec_enet_itr_coal_set() just silently being a no-op, it's not clear that some future caller wouldn't have to check the bit themselves and return -EOPNOTSUPP or some other error just like the ethtool method does. Of course we could also make fec_enet_itr_coal_set() not return void, but then it's a whole different refactoring and definitely not for post-rc8.
But also, the above was what I had sent out as a "something like this?" and tested on my own hardware before heading home, and due to the imminent release, I wanted to send out the patch ASAP.
Rasmus
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