Messages in this thread | | | From | Harini Katakam <> | Date | Tue, 10 May 2022 19:27:22 +0530 | Subject | Re: [PATCH] net: macb: Increment rx bd head after allocating skb and buffer |
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Hi Paolo,
On Tue, May 10, 2022 at 6:54 PM Paolo Abeni <pabeni@redhat.com> wrote: > > Hello, > > On Mon, 2022-05-09 at 17:49 +0530, Harini Katakam wrote: > > In gem_rx_refill rx_prepared_head is incremented at the beginning of > > the while loop preparing the skb and data buffers. If the skb or data > > buffer allocation fails, this BD will be unusable BDs until the head > > loops back to the same BD (and obviously buffer allocation succeeds). > > In the unlikely event that there's a string of allocation failures, > > there will be an equal number of unusable BDs and an inconsistent RX > > BD chain. Hence increment the head at the end of the while loop to be > > clean. > > > > Signed-off-by: Harini Katakam <harini.katakam@xilinx.com> > > Signed-off-by: Michal Simek <michal.simek@xilinx.com> > > Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com> > > This looks like targeting the "net" tree, please repost adding a > suitable Fixes tag.
Thanks for the review. This behavior would theoretically have been the same since GEM RX path handling was introduced ~9 yrs ago but I'm not sure since I cannot reproduce. Probably this? https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/net/ethernet/cadence?id=4df95131ea803bcb94f472d465c73ed57015c470 Also, this patch can't be backported to stable branches so far back since the driver files have changed. It can also be queued for net-next instead.
Regards, Harini
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