> -----Original Message-----
> From: Simon Horman <[email protected]>
> Sent: Friday, December 6, 2024 5:30 AM
> To: Nadezhdin, Anton <[email protected]>
> Cc: [email protected]; [email protected]; Nguyen, Anthony
> L
> <[email protected]>; Kitszel, Przemyslaw
> <[email protected]>; [email protected]; Keller, Jacob E
> <[email protected]>; Kolacinski, Karol <[email protected]>;
> Olech,
> Milena <[email protected]>
> Subject: Re: [PATCH iwl-next 1/5] ice: use rd32_poll_timeout_atomic in
> ice_read_phy_tstamp_ll_e810
>
> On Wed, Dec 04, 2024 at 01:03:44PM -0500, Anton Nadezhdin wrote:
> > From: Jacob Keller <[email protected]>
> >
> > The ice_read_phy_tstamp_ll_e810 function repeatedly reads the PF_SB_ATQBAL
> > register until the TS_LL_READ_TS bit is cleared. This is a perfect
> > candidate for using rd32_poll_timeout. However, the default implementation
> > uses a sleep-based wait.
> >
> > Add a new rd32_poll_timeout_atomic macro which is based on the non-
> sleeping
> > read_poll_timeout_atomic implementation. Use this to replace the loop
> > reading in the ice_read_phy_tstamp_ll_e810 function.
> >
> > This will also be used in the future when low latency PHY timer updates are
> > supported.
> >
> > Co-developed-by: Karol Kolacinski <[email protected]>
> > Signed-off-by: Karol Kolacinski <[email protected]>
> > Signed-off-by: Jacob Keller <[email protected]>
> > Reviewed-by: Milena Olech <[email protected]>
> > Signed-off-by: Anton Nadezhdin <[email protected]>
> > ---
> > drivers/net/ethernet/intel/ice/ice_osdep.h | 3 +++
> > drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 30 +++++++++------------
> > drivers/net/ethernet/intel/ice/ice_ptp_hw.h | 2 +-
> > 3 files changed, 17 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/ice/ice_osdep.h
> b/drivers/net/ethernet/intel/ice/ice_osdep.h
> > index b9f383494b3f..9bb343de80a9 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_osdep.h
> > +++ b/drivers/net/ethernet/intel/ice/ice_osdep.h
> > @@ -26,6 +26,9 @@
> >
> > #define rd32_poll_timeout(a, addr, val, cond, delay_us, timeout_us) \
> > read_poll_timeout(rd32, val, cond, delay_us, timeout_us, false, a, addr)
> > +#define rd32_poll_timeout_atomic(a, addr, val, cond, delay_us, timeout_us)
> > \
> > + read_poll_timeout_atomic(rd32, val, cond, delay_us, timeout_us, false, \
> > + a, addr)
> >
> > #define ice_flush(a) rd32((a), GLGEN_STAT)
> > #define ICE_M(m, s) ((m ## U) << (s))
> > diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
> b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
> > index e55aeab0975c..b9cf8ce9644a 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
> > @@ -4868,32 +4868,28 @@ static int
> > ice_read_phy_tstamp_ll_e810(struct ice_hw *hw, u8 idx, u8 *hi, u32 *lo)
> > {
> > u32 val;
> > - u8 i;
> > + u8 err;
> >
> > /* Write TS index to read to the PF register so the FW can read it */
> > val = FIELD_PREP(TS_LL_READ_TS_IDX, idx) | TS_LL_READ_TS;
> > wr32(hw, PF_SB_ATQBAL, val);
> >
> > /* Read the register repeatedly until the FW provides us the TS */
> > - for (i = TS_LL_READ_RETRIES; i > 0; i--) {
> > - val = rd32(hw, PF_SB_ATQBAL);
> > -
> > - /* When the bit is cleared, the TS is ready in the register */
> > - if (!(FIELD_GET(TS_LL_READ_TS, val))) {
> > - /* High 8 bit value of the TS is on the bits 16:23 */
> > - *hi = FIELD_GET(TS_LL_READ_TS_HIGH, val);
> > + err = rd32_poll_timeout_atomic(hw, PF_SB_ATQBAL, val,
> > + !FIELD_GET(TS_LL_READ_TS, val),
> > + 10, TS_LL_READ_TIMEOUT);
>
> Hi Jakob and Karol,
>
> A minor nit from my side: rd32_poll_timeout_atomic may return a negative
> error value but err is unsigned. This doesn't seem ideal.
>
> Flagged by Smatch
>
Yep, err should just be an integer here.
Thanks,
Jake
> > + if (err) {
> > + ice_debug(hw, ICE_DBG_PTP, "Failed to read PTP timestamp using
> low latency read\n");
> > + return err;
> > + }
> >
> > - /* Read the low 32 bit value and set the TS valid bit */
> > - *lo = rd32(hw, PF_SB_ATQBAH) | TS_VALID;
> > - return 0;
> > - }
> > + /* High 8 bit value of the TS is on the bits 16:23 */
> > + *hi = FIELD_GET(TS_LL_READ_TS_HIGH, val);
> >
> > - udelay(10);
> > - }
> > + /* Read the low 32 bit value and set the TS valid bit */
> > + *lo = rd32(hw, PF_SB_ATQBAH) | TS_VALID;
> >
> > - /* FW failed to provide the TS in time */
> > - ice_debug(hw, ICE_DBG_PTP, "Failed to read PTP timestamp using low
> latency read\n");
> > - return -EINVAL;
> > + return 0;
> > }
> >
> > /**
>
> ...
