Thread (4 messages) 4 messages, 2 authors, 2025-11-12

Re: [PATCH net] net: ps3_gelic_net: handle skb allocation failures

From: Jakub Kicinski <kuba@kernel.org>
Date: 2025-11-12 14:31:45
Also in: lkml, netdev

On Wed, 12 Nov 2025 10:34:01 +0100 Florian Fuchs wrote:
quoted
quoted
--- a/drivers/net/ethernet/toshiba/ps3_gelic_net.c
+++ b/drivers/net/ethernet/toshiba/ps3_gelic_net.c
@@ -259,6 +259,7 @@ void gelic_card_down(struct gelic_card *card)
 	mutex_lock(&card->updown_lock);
 	if (atomic_dec_if_positive(&card->users) == 0) {
 		pr_debug("%s: real do\n", __func__);
+		timer_delete_sync(&card->rx_oom_timer);
 		napi_disable(&card->napi);  
I think the ordering here should be inverted  
I thought, that there might be a race condition in the inverted order
like that napi gets re-enabled by the timer in between of the down:

1. napi_disable
2. rx_oom_timer runs and calls napi_schedule again
3. timer_delete_sync

So the timer is deleted first, to prevent any possibility to run.
napi_disable() makes napi_schedule() a nop (it makes it look like it's
already scheduled).
quoted
TBH handling the OOM inside the Rx function seems a little fragile.
What if there is a packet to Rx as we enter. I don't see any loop here
it just replaces the used buffer..  
I am not sure, the handling needs to happen, when the skb allocation
fails, and that happens in the rx function, right? I am open to better
fitting fix position.
Purely from the structure of the code PoV it'd be cleaner if the
alloc/refill was separate from the processing so we can call just 
that part.

But looking closer I think the handling is fine as is. So I think
just addressing the nits is fine for v2
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