Re: [PATCH v5 07/10] scsi: ufs: ufs-qcom: Set initial PHY gear to max HS gear for HW ver 5 and newer

Manivannan Sadhasivam
2023-11-28T10:59:15Z

On Tue, Nov 28, 2023 at 03:58:42PM +0800, Can Guo wrote:
> Hi Mani,
>
> On 11/28/2023 2:00 PM, Manivannan Sadhasivam wrote:
> > On Thu, Nov 23, 2023 at 12:46:27AM -0800, Can Guo wrote:
> > > Set the initial PHY gear to max HS gear for hosts with HW ver 5 and newer.
> > >
> >
> > MAX_GEAR will be used for hosts with hw_ver.major >= 4
>
> I put it > 5 because I am not intent to touch any old targets which has
> proven working fine with starting with PHY gear HS_G2. If I put it >= 4,
> there would be many targets impacted by this change. I need to go back and
> test those platforms (HW ver == 4).
>

This assumption will make the code hard to maintain. I think if you happen to
test it on atleast a couple of old targets it should be good since I do not see
how others can fail.

- Mani

> Thanks,
> Can Guo.
>
> >
> > > This patch is not changing any functionalities or logic but only a
> > > preparation patch for the next patch in this series.
> > >
> > > Signed-off-by: Can Guo <quic_cang@quicinc.com>
> > > ---
> > > drivers/ufs/host/ufs-qcom.c | 21 +++++++++++++++------
> > > 1 file changed, 15 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> > > index 6756f8d..7bbccf4 100644
> > > --- a/drivers/ufs/host/ufs-qcom.c
> > > +++ b/drivers/ufs/host/ufs-qcom.c
> > > @@ -1067,6 +1067,20 @@ static void ufs_qcom_advertise_quirks(struct ufs_hba *hba)
> > > hba->quirks |= UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH;
> > > }
> > > +static void ufs_qcom_set_phy_gear(struct ufs_qcom_host *host)
> > > +{
> > > + struct ufs_host_params *host_params = &host->host_params;
> > > +
> > > + host->phy_gear = host_params->hs_tx_gear;
> > > +
> > > + /*
> > > + * Power up the PHY using the minimum supported gear (UFS_HS_G2).
> > > + * Switching to max gear will be performed during reinit if supported.
> >
> > You need to reword this comment too.
> >
> > > + */
> > > + if (host->hw_ver.major < 0x5)
> >
> > As I mentioned above, MAX_GEAR will be used if hw_ver.major is >=4 in
> > ufs_qcom_get_hs_gear(). So this check should be (< 0x4).
> >
> > - Mani
> >
> > > + host->phy_gear = UFS_HS_G2;
> > > +}
> > > +
> > > static void ufs_qcom_set_host_params(struct ufs_hba *hba)
> > > {
> > > struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> > > @@ -1303,6 +1317,7 @@ static int ufs_qcom_init(struct ufs_hba *hba)
> > > ufs_qcom_set_caps(hba);
> > > ufs_qcom_advertise_quirks(hba);
> > > ufs_qcom_set_host_params(hba);
> > > + ufs_qcom_set_phy_gear(host);
> > > err = ufs_qcom_ice_init(host);
> > > if (err)
> > > @@ -1320,12 +1335,6 @@ static int ufs_qcom_init(struct ufs_hba *hba)
> > > dev_warn(dev, "%s: failed to configure the testbus %d\n",
> > > __func__, err);
> > > - /*
> > > - * Power up the PHY using the minimum supported gear (UFS_HS_G2).
> > > - * Switching to max gear will be performed during reinit if supported.
> > > - */
> > > - host->phy_gear = UFS_HS_G2;
> > > -
> > > return 0;
> > > out_variant_clear:
> > > --
> > > 2.7.4
> > >
> >

--
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