On Tue, Jan 23, 2024 at 01:13:36PM -0600, Andrew Halaney wrote: > The comments that currently are within the hw_ver < 4 conditional > are misleading. They really apply to various branches of the > conditionals there and incorrectly state that the phy_gear value > can increase. > > Right now the logic is to: > > * Default to max supported gear for phy_gear > * Set phy_gear to minimum value if version < 4 since those versions > only support one PHY init sequence (and therefore don't need reinit) > * Set phy_gear to the optimal value if the device version is already > populated in the controller registers on boot > > Let's move some of the comment to outside the if statement and clean up > the bit left about switching to a higher gear on reinit. This way the > comment more accurately reflects the logic. > > Signed-off-by: Andrew Halaney <ahalaney@xxxxxxxxxx> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx> - Mani > --- > This is a minor comment cleanup inspired by my mistaken understanding of > the flow over at [0] > > [0] https://lore.kernel.org/linux-arm-msm/20240123143615.GD19029@thinkpad/ > --- > drivers/ufs/host/ufs-qcom.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c > index 39eef470f8fa..d9ec2dfbbda4 100644 > --- a/drivers/ufs/host/ufs-qcom.c > +++ b/drivers/ufs/host/ufs-qcom.c > @@ -843,15 +843,20 @@ static void ufs_qcom_set_phy_gear(struct ufs_qcom_host *host) > struct ufs_host_params *host_params = &host->host_params; > u32 val, dev_major; > > + /* > + * Default to powering up the PHY to the max gear possible, which is > + * backwards compatible with lower gears but not optimal from > + * a power usage point of view. After device negotiation, if the > + * gear is lower a reinit will be performed to program the PHY > + * to the ideal gear for this combo of controller and device. > + */ > host->phy_gear = host_params->hs_tx_gear; > > if (host->hw_ver.major < 0x4) { > /* > - * For controllers whose major HW version is < 4, power up the > - * PHY using minimum supported gear (UFS_HS_G2). Switching to > - * max gear will be performed during reinit if supported. > - * For newer controllers, whose major HW version is >= 4, power > - * up the PHY using max supported gear. > + * These controllers only have one PHY init sequence, > + * let's power up the PHY using that (the minimum supported > + * gear, UFS_HS_G2). > */ > host->phy_gear = UFS_HS_G2; > } else if (host->hw_ver.major >= 0x5) { > > --- > base-commit: 319fbd8fc6d339e0a1c7b067eed870c518a13a02 > change-id: 20240123-ufs-reinit-comments-17c44af62651 > > Best regards, > -- > Andrew Halaney <ahalaney@xxxxxxxxxx> > -- மணிவண்ணன் சதாசிவம்
