On Sun, Jan 4, 2026 at 11:19 PM Loktionov, Aleksandr < [email protected]> wrote:
> > > > -----Original Message----- > > From: Intel-wired-lan <[email protected]> On Behalf > > Of Li Li via Intel-wired-lan > > Sent: Monday, January 5, 2026 7:47 AM > > To: Nguyen, Anthony L <[email protected]>; Kitszel, > > Przemyslaw <[email protected]>; David S. Miller > > <[email protected]>; Jakub Kicinski <[email protected]>; Eric Dumazet > > <[email protected]>; [email protected] > > Cc: [email protected]; [email protected]; David > > Decotigny <[email protected]>; Singhai, Anjali > > <[email protected]>; Samudrala, Sridhar > > <[email protected]>; Brian Vazquez <[email protected]>; > > Tantilov, Emil S <[email protected]>; Li Li > > <[email protected]> > > Subject: [Intel-wired-lan] [PATCH v2] idpf: increment completion queue > > next_to_clean in sw marker wait routine > > > > Currently, in idpf_wait_for_sw_marker_completion(), when an > > IDPF_TXD_COMPLT_SW_MARKER packet is found, the routine breaks out of > > the for loop and does not increment the next_to_clean counter. This > > causes the subsequent NAPI polls to run into the same > > IDPF_TXD_COMPLT_SW_MARKER packet again and print out the following: > > > > [ 23.261341] idpf 0000:05:00.0 eth1: Unknown TX completion type: > > 5 > > > > Instead, we should increment next_to_clean regardless when an > > IDPF_TXD_COMPLT_SW_MARKER packet is found. > > > > Tested: with the patch applied, we do not see the errors above from > > NAPI polls anymore. > > > > Signed-off-by: Li Li <[email protected]> > > --- > > Changes in v2: > > - Initialize idpf_tx_queue *target to NULL to suppress the "'target' > > uninitialized when 'if' statement is true warning". > > > > drivers/net/ethernet/intel/idpf/idpf_txrx.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c > > b/drivers/net/ethernet/intel/idpf/idpf_txrx.c > > index 69bab7187e541..452d0a9e83a4f 100644 > > --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c > > +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c > > @@ -2326,7 +2326,7 @@ void idpf_wait_for_sw_marker_completion(const > > struct idpf_tx_queue *txq) > > > > do { > > struct idpf_splitq_4b_tx_compl_desc *tx_desc; > > - struct idpf_tx_queue *target; > > + struct idpf_tx_queue *target = NULL; > Linux kernel is against premature initialization just to silence a > compiler. > The target variable is dereferenced at idpf_queue_clear(SW_MARKER, target)) > but can remain uninitialized if execution jumps to the next: label via a > goto > before target is assigned. > Isn't it? > That is correct. When the following if statement (line 2341-2343) evaluates to true: if (FIELD_GET(IDPF_TXD_COMPLQ_COMPL_TYPE_M, ctype_gen) != IDPF_TXD_COMPLT_SW_MARKER) goto next; Then the initialization at line 2346: target = complq->txq_grp->txqs[id]; would be skipped, making "target" uninitialized. Therefore, in this patch, I need to initialize "target" to NULL. > > u32 ctype_gen, id; > > > > tx_desc = flow ? &complq->comp[ntc].common : > > @@ -2346,14 +2346,14 @@ void idpf_wait_for_sw_marker_completion(const > > struct idpf_tx_queue *txq) > > target = complq->txq_grp->txqs[id]; > > > > idpf_queue_clear(SW_MARKER, target); > > - if (target == txq) > > - break; > > > > next: > > if (unlikely(++ntc == complq->desc_count)) { > > ntc = 0; > > gen_flag = !gen_flag; > > } > > + if (target == txq) > Are tou sure that incremented ntc value is ever written back to > complq->next_to_clean? > Yes, the value of "ntc" is written back to "complq->next_to_clean" at the end of the function (at line 2360): complq->next_to_clean = ntc; > > > + break; > > } while (time_before(jiffies, timeout)); > > > > idpf_queue_assign(GEN_CHK, complq, gen_flag); > > -- > > 2.52.0.351.gbe84eed79e-goog > >
