Re: [net-next PATCH v3] octeontx2-pf: Use PTP HW timestamp counter atomic update feature

[Sai Krishna Gajula]

> -----Original Message-----
> From: Leon Romanovsky <leon@xxxxxxxxxx>
> Sent: Saturday, August 19, 2023 12:19 AM
> To: Sai Krishna Gajula <saikrishnag@xxxxxxxxxxx>
> Cc: davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx;
> pabeni@xxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; Sunil Kovvuri Goutham <sgoutham@xxxxxxxxxxx>;
> Geethasowjanya Akula <gakula@xxxxxxxxxxx>; Subbaraya Sundeep Bhatta
> <sbhatta@xxxxxxxxxxx>; Hariprasad Kelam <hkelam@xxxxxxxxxxx>;
> richardcochran@xxxxxxxxx; kalesh-anakkur.purayil@xxxxxxxxxxxx; Naveen
> Mamindlapalli <naveenm@xxxxxxxxxxx>
> Subject: Re: [net-next PATCH v3] octeontx2-pf: Use PTP HW timestamp
> counter atomic update feature
> 
> On Thu, Aug 17, 2023 at 11:13:51PM +0530, Sai Krishna wrote:
> > Some of the newer silicon versions in CN10K series supports a feature
> > where in the current PTP timestamp in HW can be updated atomically
> > without losing any cpu cycles unlike read/modify/write register.
> > This patch uses this feature so that PTP accuracy can be improved
> > while adjusting the master offset in HW. There is no need for SW
> > timecounter when using this feature. So removed references to SW
> > timecounter wherever appropriate.
> >
> > Signed-off-by: Sai Krishna <saikrishnag@xxxxxxxxxxx>
> > Signed-off-by: Naveen Mamindlapalli <naveenm@xxxxxxxxxxx>
> > Signed-off-by: Sunil Kovvuri Goutham <sgoutham@xxxxxxxxxxx>
> > Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@xxxxxxxxxxxx>
> > ---
> > v3:
> >     - Addressed review comments given by Jakub Kicinski
> >         1. Fixed re-ordering of headers in alphabetical order
> >         2. Refactored SoC revision identification logic
> >         3. CN10K errata revisions can be different from atomic update
> >            supported revision devices.
> >         4. Removed ptp device check.
> > v2:
> >     - Addressed review comments given by Simon Horman, Kalesh Anakkur
> Purayil
> > 	1. Removed inline keyword for function in .c file
> >         2. Modified/optimized conditions related boolean
> >
> >  .../net/ethernet/marvell/octeontx2/af/mbox.h  |  12 ++
> >  .../net/ethernet/marvell/octeontx2/af/ptp.c   | 155 ++++++++++++++--
> >  .../net/ethernet/marvell/octeontx2/af/ptp.h   |   3 +-
> >  .../net/ethernet/marvell/octeontx2/af/rvu.c   |   2 +-
> >  .../net/ethernet/marvell/octeontx2/af/rvu.h   |  12 ++
> >  .../marvell/octeontx2/nic/otx2_common.h       |   1 +
> >  .../ethernet/marvell/octeontx2/nic/otx2_ptp.c | 174
> > ++++++++++++++----
> >  7 files changed, 304 insertions(+), 55 deletions(-)
> 
> <...>
> 
> > +static bool is_tstmp_atomic_update_supported(struct otx2_ptp *ptp) {
> > +	struct ptp_get_cap_rsp *rsp;
> > +	struct msg_req *req;
> > +	int err;
> > +
> > +	if (!ptp->nic)
> > +		return false;
> > +
> > +	mutex_lock(&ptp->nic->mbox.lock);
> > +	req = otx2_mbox_alloc_msg_ptp_get_cap(&ptp->nic->mbox);
> > +	if (!req)
> > +		return false;
> > +
> > +	err = otx2_sync_mbox_msg(&ptp->nic->mbox);
> > +	if (err)
> > +		return false;
> 
> Shouldn't you call to mutex_unlock() in two returns above?

Ack, will submit V4 patch.

Thanks
Sai
> 
> Thanks
> 
> > +
> > +	rsp = (struct ptp_get_cap_rsp *)otx2_mbox_get_rsp(&ptp->nic-
> >mbox.mbox, 0,
> > +							  &req->hdr);
> > +	mutex_unlock(&ptp->nic->mbox.lock);
> > +
> > +	if (IS_ERR(rsp))
> > +		return false;
> > +
> > +	if (rsp->cap & PTP_CAP_HW_ATOMIC_UPDATE)
> > +		return true;
> > +
> > +	return false;
> > +}