From d7795f8f26d944ede937d750b1804c080edf86c3 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sun, 14 Feb 2021 00:37:51 +0200 Subject: net: mscc: ocelot: only drain extraction queue on error It appears that the intention of this snippet of code is to not exit ocelot_xtr_irq_handler() while in the middle of extracting a frame. The problem in extracting it word by word is that future extraction attempts are really easy to get desynchronized, since the IRQ handler assumes that the first 16 bytes are the IFH, which give further information about the frame, such as frame length. But during normal operation, "err" will not be 0, but 4, set from here: for (i = 0; i < OCELOT_TAG_LEN / 4; i++) { err = ocelot_rx_frame_word(ocelot, grp, true, &ifh[i]); if (err != 4) break; } if (err != 4) break; In that case, draining the extraction queue is a no-op. So explicitly make this code execute only on negative err. Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- drivers/net/ethernet/mscc/ocelot_vsc7514.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/net/ethernet/mscc/ocelot_vsc7514.c b/drivers/net/ethernet/mscc/ocelot_vsc7514.c index 590297d5e144..d19efbe6ffd3 100644 --- a/drivers/net/ethernet/mscc/ocelot_vsc7514.c +++ b/drivers/net/ethernet/mscc/ocelot_vsc7514.c @@ -701,7 +701,7 @@ static irqreturn_t ocelot_xtr_irq_handler(int irq, void *arg) dev->stats.rx_packets++; } - if (err) + if (err < 0) while (ocelot_read(ocelot, QS_XTR_DATA_PRESENT) & BIT(grp)) ocelot_read_rix(ocelot, QS_XTR_RD, grp); -- cgit v1.2.3