| Message ID | 20250304114652.210395-1-arthur.simchaev@sandisk.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | ufs: core: bsg: Add hibern8 enter/exit to ufshcd_send_bsg_uic_cmd | expand |
Arthur, At present, we lack a user-space tool to initiate eye monitor measurements. Additionally, opening a channel for users in user land to send MP commands seems unsafe. Kind regards, Bean On Tue, 2025-03-04 at 13:46 +0200, Arthur Simchaev wrote: > Eye monitor measurement functionality was added to the M-PHY v5 > specification. The measurement of the eye monitor signal for the UFS > device begins when the link enters the hibernate state. > Hence, allow user-layer applications the capability to send the > hibern8 > enter command through the BSG framework. For completion, allow the > sibling functionality of hibern8 exit as well. > > Signed-off-by: Arthur Simchaev <arthur.simchaev@sandisk.com> > --- > drivers/ufs/core/ufshcd.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > index 4e1e214fc5a2..546ab557a77c 100644 > --- a/drivers/ufs/core/ufshcd.c > +++ b/drivers/ufs/core/ufshcd.c > @@ -4366,6 +4366,16 @@ int ufshcd_send_bsg_uic_cmd(struct ufs_hba > *hba, struct uic_command *uic_cmd) > goto out; > } > > + if (uic_cmd->command == UIC_CMD_DME_HIBER_ENTER) { > + ret = ufshcd_uic_hibern8_enter(hba); > + goto out; > + } > + > + if (uic_cmd->command == UIC_CMD_DME_HIBER_EXIT) { > + ret = ufshcd_uic_hibern8_exit(hba); > + goto out; > + } > + > mutex_lock(&hba->uic_cmd_mutex); > ufshcd_add_delay_before_dme_cmd(hba); > > -- > 2.34.1
Hi Arthur, On 3/6/2025 8:50 PM, Bean Huo wrote: > Arthur, > > At present, we lack a user-space tool to initiate eye monitor > measurements. Additionally, opening a channel for users in user land to > send MP commands seems unsafe. > > > Kind regards, > Bean > > On Tue, 2025-03-04 at 13:46 +0200, Arthur Simchaev wrote: >> Eye monitor measurement functionality was added to the M-PHY v5 >> specification. The measurement of the eye monitor signal for the UFS >> device begins when the link enters the hibernate state. >> Hence, allow user-layer applications the capability to send the >> hibern8 >> enter command through the BSG framework. For completion, allow the >> sibling functionality of hibern8 exit as well. >> >> Signed-off-by: Arthur Simchaev <arthur.simchaev@sandisk.com> >> --- >> drivers/ufs/core/ufshcd.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c >> index 4e1e214fc5a2..546ab557a77c 100644 >> --- a/drivers/ufs/core/ufshcd.c >> +++ b/drivers/ufs/core/ufshcd.c >> @@ -4366,6 +4366,16 @@ int ufshcd_send_bsg_uic_cmd(struct ufs_hba >> *hba, struct uic_command *uic_cmd) >> goto out; >> } >> >> + if (uic_cmd->command == UIC_CMD_DME_HIBER_ENTER) { >> + ret = ufshcd_uic_hibern8_enter(hba); >> + goto out; >> + } >> + >> + if (uic_cmd->command == UIC_CMD_DME_HIBER_EXIT) { >> + ret = ufshcd_uic_hibern8_exit(hba); >> + goto out; >> + } >> + >> mutex_lock(&hba->uic_cmd_mutex); >> ufshcd_add_delay_before_dme_cmd(hba); >> >> -- >> 2.34.1 I can understand that you want to use hibern8 enter&exit to trigger a RCT to kick start the EOM, however there is a better/simpler way to do so: you can trigger a power mode change to the same power mode (e.g., from HS-G5 to HS-G5) to trigger a RCT (without invoking hibern8 enter&exit) from user layer by dme_set(PA_PWRMODE). FYI, we have open-sourced Qcom's EOM tool in GitHub and validated the EOM function on most UFS4.x devices from UFS vendors, you can find the code for your reference: https://github.com/quic/ufs-tools/blob/main/ufs-cli/ufs_eom.c#L266 The recent change from Ziqi Chen is to serve the power mode change purpose I mentioned above: https://lore.kernel.org/all/20241212144248.990103107@linuxfoudation.org/ Hope above info can help you. Thanks, Can Guo.
> I can understand that you want to use hibern8 enter&exit to trigger a RCT to > kick start the EOM, however there is a better/simpler way to do so: you can > trigger a power mode change to the same power mode (e.g., from HS-G5 to > HS-G5) to trigger a RCT (without invoking hibern8 enter&exit) from user layer > by dme_set(PA_PWRMODE). > > FYI, we have open-sourced Qcom's EOM tool in GitHub and validated the EOM > function on most UFS4.x devices from UFS vendors, you can find the code for > your reference: > https://github.com/quic/ufs-tools/blob/main/ufs-cli/ufs_eom.c#L266 > > The recent change from Ziqi Chen is to serve the power mode change purpose > I mentioned above: > https://lore.kernel.org/all/20241212144248.990103107@linuxfoudation.or > g/ > > Hope above info can help you. > > Thanks, > Can Guo. Thank you, Can. I am familiar with this very useful tool. In fact, I published the patch due to the tool In order to extend the debug functionality from the user space. In my opinion, the hibern8 enter function can be used in a similar manner as the PMC. For instance, if the host fails to change the power mode to FAST MODE with NO ADAPT. Regards Arthur
> -----Original Message----- > From: Bean Huo <huobean@gmail.com> > Sent: Thursday, March 6, 2025 2:50 PM > To: Arthur Simchaev <Arthur.Simchaev@sandisk.com>; > martin.petersen@oracle.com; quic_mapa@quicinc.com; > quic_cang@quicinc.com > Cc: Avri Altman <Avri.Altman@sandisk.com>; Avi Shchislowski > <Avi.Shchislowski@sandisk.com>; linux-scsi@vger.kernel.org; linux- > kernel@vger.kernel.org; bvanassche@acm.org > Subject: Re: [PATCH] ufs: core: bsg: Add hibern8 enter/exit to > ufshcd_send_bsg_uic_cmd > > > Arthur, > > At present, we lack a user-space tool to initiate eye monitor measurements. > Additionally, opening a channel for users in user land to send MP commands > seems unsafe. > > > Kind regards, > Bean > Hi Bean. Actually, the EOM tool was published two months ago See the mail from Can Guo. The patch simply extends the UIC debugging functionality from user space. I think it is quite safe to use hibern8 functionality for debugging purposes. Regards Arthur
On Fri, 2025-03-07 at 09:18 +0000, Arthur Simchaev wrote: > > > > -----Original Message----- > > From: Bean Huo <huobean@gmail.com> > > Sent: Thursday, March 6, 2025 2:50 PM > > To: Arthur Simchaev <Arthur.Simchaev@sandisk.com>; > > martin.petersen@oracle.com; quic_mapa@quicinc.com; > > quic_cang@quicinc.com > > Cc: Avri Altman <Avri.Altman@sandisk.com>; Avi Shchislowski > > <Avi.Shchislowski@sandisk.com>; linux-scsi@vger.kernel.org; linux- > > kernel@vger.kernel.org; bvanassche@acm.org > > Subject: Re: [PATCH] ufs: core: bsg: Add hibern8 enter/exit to > > ufshcd_send_bsg_uic_cmd > > > > > > Arthur, > > > > At present, we lack a user-space tool to initiate eye monitor > > measurements. > > Additionally, opening a channel for users in user land to send MP > > commands > > seems unsafe. > > > > > > Kind regards, > > Bean > > > > Hi Bean. > > Actually, the EOM tool was published two months ago > See the mail from Can Guo. The patch simply extends the UIC debugging > functionality from user space. > I think it is quite safe to use hibern8 functionality for debugging > purposes. > > Regards > Arthur Great, we will work on that. Kind regards, Bean
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 4e1e214fc5a2..546ab557a77c 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -4366,6 +4366,16 @@ int ufshcd_send_bsg_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd) goto out; } + if (uic_cmd->command == UIC_CMD_DME_HIBER_ENTER) { + ret = ufshcd_uic_hibern8_enter(hba); + goto out; + } + + if (uic_cmd->command == UIC_CMD_DME_HIBER_EXIT) { + ret = ufshcd_uic_hibern8_exit(hba); + goto out; + } + mutex_lock(&hba->uic_cmd_mutex); ufshcd_add_delay_before_dme_cmd(hba);
Eye monitor measurement functionality was added to the M-PHY v5 specification. The measurement of the eye monitor signal for the UFS device begins when the link enters the hibernate state. Hence, allow user-layer applications the capability to send the hibern8 enter command through the BSG framework. For completion, allow the sibling functionality of hibern8 exit as well. Signed-off-by: Arthur Simchaev <arthur.simchaev@sandisk.com> --- drivers/ufs/core/ufshcd.c | 10 ++++++++++ 1 file changed, 10 insertions(+)