RE: [Intel-wired-lan] [iwl-net PATCH] idpf: reduce mbx_task schedule delay to 300us

[Salin, Samuel]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf Of
> Loktionov, Aleksandr
> Sent: Wednesday, November 12, 2025 5:06 AM
> To: Brian Vazquez <brianvv@xxxxxxxxxx>; Brian Vazquez
> <brianvv.kernel@xxxxxxxxx>; Nguyen, Anthony L
> <anthony.l.nguyen@xxxxxxxxx>; Kitszel, Przemyslaw
> <przemyslaw.kitszel@xxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> Eric Dumazet <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>;
> Paolo Abeni <pabeni@xxxxxxxxxx>; intel-wired-lan@xxxxxxxxxxxxxxxx
> Cc: David Decotigny <decot@xxxxxxxxxx>; Singhai, Anjali
> <anjali.singhai@xxxxxxxxx>; Samudrala, Sridhar
> <sridhar.samudrala@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> netdev@xxxxxxxxxxxxxxx; Tantilov, Emil S <emil.s.tantilov@xxxxxxxxx>
> Subject: Re: [Intel-wired-lan] [iwl-net PATCH] idpf: reduce mbx_task schedule
> delay to 300us
> 
> 
> 
> > -----Original Message-----
> > From: Intel-wired-lan <intel-wired-lan-bounces@xxxxxxxxxx> On Behalf
> > Of Brian Vazquez
> > Sent: Monday, November 10, 2025 9:59 PM
> > To: Brian Vazquez <brianvv.kernel@xxxxxxxxx>; Nguyen, Anthony L
> > <anthony.l.nguyen@xxxxxxxxx>; Kitszel, Przemyslaw
> > <przemyslaw.kitszel@xxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> > Eric Dumazet <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>;
> > Paolo Abeni <pabeni@xxxxxxxxxx>; intel-wired-lan@xxxxxxxxxxxxxxxx
> > Cc: David Decotigny <decot@xxxxxxxxxx>; Singhai, Anjali
> > <anjali.singhai@xxxxxxxxx>; Samudrala, Sridhar
> > <sridhar.samudrala@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx;
> > netdev@xxxxxxxxxxxxxxx; Tantilov, Emil S <emil.s.tantilov@xxxxxxxxx>;
> > Brian Vazquez <brianvv@xxxxxxxxxx>
> > Subject: [Intel-wired-lan] [iwl-net PATCH] idpf: reduce mbx_task
> > schedule delay to 300us
> >
> > During the IDPF init phase, the mailbox runs in poll mode until it is
> > configured to properly handle interrupts. The previous delay of 300ms
> > is excessively long for the mailbox polling mechanism, which causes a
> > slow initialization of ~2s:
> >
> > echo 0000:06:12.4 > /sys/bus/pci/drivers/idpf/bind
> >
> > [   52.444239] idpf 0000:06:12.4: enabling device (0000 -> 0002)
> > [   52.485005] idpf 0000:06:12.4: Device HW Reset initiated
> > [   54.177181] idpf 0000:06:12.4: PTP init failed, err=-EOPNOTSUPP
> > [   54.206177] idpf 0000:06:12.4: Minimum RX descriptor support not
> > provided, using the default
> > [   54.206182] idpf 0000:06:12.4: Minimum TX descriptor support not
> > provided, using the default
> >
> > Changing the delay to 300us avoids the delays during the initial
> > mailbox transactions, making the init phase much faster:
> >
> > [   83.342590] idpf 0000:06:12.4: enabling device (0000 -> 0002)
> > [   83.384402] idpf 0000:06:12.4: Device HW Reset initiated
> > [   83.518323] idpf 0000:06:12.4: PTP init failed, err=-EOPNOTSUPP
> > [   83.547430] idpf 0000:06:12.4: Minimum RX descriptor support not
> > provided, using the default
> > [   83.547435] idpf 0000:06:12.4: Minimum TX descriptor support not
> > provided, using the default
> >
> > Signed-off-by: Brian Vazquez <brianvv@xxxxxxxxxx>
> > ---
> 
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@xxxxxxxxx>

Tested-by: Samuel Salin <Samuel.salin@xxxxxxxxx>