On Wed, Nov 29, 2023 at 08:10:57PM +0800, Ziqi Chen wrote:
>
>
> On 11/28/2023 7:27 PM, Manivannan Sadhasivam wrote:
> > On Tue, Nov 28, 2023 at 03:40:57AM +0800, Ziqi Chen wrote:
> > >
> > >
> > > On 11/22/2023 2:14 PM, Can Guo wrote:
> > > >
> > > >
> > > > On 10/25/2023 3:41 PM, Manivannan Sadhasivam wrote:
> > > > > On Tue, Oct 24, 2023 at 07:10:15PM +0800, Ziqi Chen wrote:
> > > > > > During PISI test, we found the issue that host Tx still bursting after
> > > > >
> > > > > What is PISI test?
> > >
> > > SI measurement.
> > >
> >
> > Please expand it in the patch description.
>
> Sure, I will update in next patch version.
>
> >
> > > > >
> > > > > > H/W reset. Move ufs_qcom_host_reset() to ufs_qcom_device_reset() and
> > > > > > reset host before device reset to stop tx burst.
> > > > > >
> > > > >
> > > > > device_reset() callback is supposed to reset only the device and not
> > > > > the host.
> > > > > So NACK for this patch.
> > > >
> > > > Agree, the change should come in a more reasonable way.
> > > >
> > > > Actually, similar code is already there in ufs_mtk_device_reset() in
> > > > ufs-mediatek.c, I guess here is trying to mimic that fashion.
> > > >
> > > > This change, from its functionality point of view, we do need it,
> > > > because I occasionally (2 out of 10) hit PHY error on lane 0 during
> > > > reboot test (in my case, I tried SM8350, SM8450 and SM8550， all same).
> > > >
> > > > [ 1.911188] [DEBUG]ufshcd_update_uic_error: UECPA:0x80000002
> > > > [ 1.922843] [DEBUG]ufshcd_update_uic_error: UECDL:0x80004000
> > > > [ 1.934473] [DEBUG]ufshcd_update_uic_error: UECN:0x0
> > > > [ 1.944688] [DEBUG]ufshcd_update_uic_error: UECT:0x0
> > > > [ 1.954901] [DEBUG]ufshcd_update_uic_error: UECDME:0x0
> > > >
> > > > I found out that the PHY error pops out right after UFS device gets
> > > > reset in the 2nd init. After having this change in place, the PA/DL
> > > > errors are gone.
> > >
> > > Hi Mani,
> > >
> > > There is another way that adding a new vops that call XXX_host_reset() from
> > > soc vendor driver. in this way, we can call this vops in core layer without
> > > the dependency of device reset.
> > > due to we already observed such error and received many same reports from
> > > different OEMs, we need to fix it in some way.
> > > if you think above way is available, I will update new patch in soon. Or
> > > could you give us other suggestion?
> > >
> >
> > First, please describe the issue in detail. How the issue is getting triggered
> > and then justify your change. I do not have access to the bug reports that you
> > received.
>
> From the waveform measured by Samsung , we can see at the end of 2nd Link
> Startup, host still keep bursting after H/W reset. This abnormal timing
> would cause the PA/DL error mentioned by Can.
>
> On the other hand, at the end of 1st Link start up, Host ends bursting at
> first and then sends H/W reset to device. So Samsung suggested to do host
> reset before every time device reset to fix this issue. That's what you saw
> in this patch. This patch has been verified by OEMs.
>
Thanks for the detail. This info should have been part of the patch description.
> So do you think if we can keep this change with details update in commit
> message. or need to do other improvement?
>
For sure we should not do host reset within device_reset callback. I'd like to
know at what point of time we are seeing the host burst after device reset. I
mean can you point me to the code in the ufshcd driver that when calling
device_reset you are seeing the issue? Then we can do a host_reset before that
_specific_ device_reset with the help of the new vops you suggested.
- Mani
>
> -Ziqi
>
> >
> > - Mani
> >
> > > -Ziqi
> > >
> > > >
> > > > Thanks,
> > > > Can Guo.
> > > > >
> > > > > - Mani
> > > > >
> > > > > > Signed-off-by: Ziqi Chen <quic_ziqichen@xxxxxxxxxxx>
> > > > > > ---
> > > > > > drivers/ufs/host/ufs-qcom.c | 13 +++++++------
> > > > > > 1 file changed, 7 insertions(+), 6 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> > > > > > index 96cb8b5..43163d3 100644
> > > > > > --- a/drivers/ufs/host/ufs-qcom.c
> > > > > > +++ b/drivers/ufs/host/ufs-qcom.c
> > > > > > @@ -445,12 +445,6 @@ static int
> > > > > > ufs_qcom_power_up_sequence(struct ufs_hba *hba)
> > > > > > struct phy *phy = host->generic_phy;
> > > > > > int ret;
> > > > > > - /* Reset UFS Host Controller and PHY */
> > > > > > - ret = ufs_qcom_host_reset(hba);
> > > > > > - if (ret)
> > > > > > - dev_warn(hba->dev, "%s: host reset returned %d\n",
> > > > > > - __func__, ret);
> > > > > > -
> > > > > > /* phy initialization - calibrate the phy */
> > > > > > ret = phy_init(phy);
> > > > > > if (ret) {
> > > > > > @@ -1709,6 +1703,13 @@ static void ufs_qcom_dump_dbg_regs(struct
> > > > > > ufs_hba *hba)
> > > > > > static int ufs_qcom_device_reset(struct ufs_hba *hba)
> > > > > > {
> > > > > > struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> > > > > > + int ret = 0;
> > > > > > +
> > > > > > + /* Reset UFS Host Controller and PHY */
> > > > > > + ret = ufs_qcom_host_reset(hba);
> > > > > > + if (ret)
> > > > > > + dev_warn(hba->dev, "%s: host reset returned %d\n",
> > > > > > + __func__, ret);
> > > > > > /* reset gpio is optional */
> > > > > > if (!host->device_reset)
> > > > > > --
> > > > > > 2.7.4
> > > > > >
> > > > >
> >
--
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