Re: [PATCH v3 5/5] Revert "scsi: ufs: disable vccq if it's not needed by UFS device"
From: Jeffrey Hugo
Date: Sun Feb 10 2019 - 10:59:06 EST
On 2/9/2019 1:42 AM, Alim Akhtar wrote:
On 08/02/19 8:29 PM, Jeffrey Hugo wrote:
On 2/8/2019 2:09 AM, Alim Akhtar wrote:
Hi Jeffrey,
On 07/02/19 8:22 PM, Jeffrey Hugo wrote:
On 2/7/2019 1:50 AM, Alim Akhtar wrote:
Hi Marc,
On 06/02/19 9:22 PM, Marc Gonzalez wrote:
On 06/02/2019 16:27, Alim Akhtar wrote:
On 06/02/19 8:29 PM, Marc Gonzalez wrote:
[ÂÂÂ 2.405734] regulator_disable: ENTER vdd_l26
[ÂÂÂ 2.405958] regulator_disable: EXIT vdd_l26
[ÂÂÂ 2.406032]ÂÂ regulator_set_load: vdd_l26 = 0 uA
[ÂÂÂ 3.930447] ufshcd-qcom 1da4000.ufshc: ufshcd_query_attr: opcode
0x04 for idn 13 failed, index 0, err = -11
[ÂÂÂ 5.434358] ufshcd-qcom 1da4000.ufshc: ufshcd_query_attr: opcode
0x04 for idn 13 failed, index 0, err = -11
[ÂÂÂ 6.938318] ufshcd-qcom 1da4000.ufshc: ufshcd_query_attr: opcode
0x04 for idn 13 failed, index 0, err = -11
[ÂÂÂ 6.938414] ufshcd-qcom 1da4000.ufshc: ufshcd_query_attr_retry:
query attribute, idn 13, failed with error -11 after 3 retires
[ÂÂÂ 6.946959] ufshcd-qcom 1da4000.ufshc:
ufshcd_disable_auto_bkops: failed to enable exception event -11
[ÂÂÂ 6.958523] ufshcd-qcom 1da4000.ufshc: dme-peer-get: attr-id
0x1587 failed 3 retries
[ÂÂÂ 6.967730] ufshcd-qcom 1da4000.ufshc: dme-peer-get: attr-id
0x1586 failed 3 retries
[ÂÂÂ 6.975576] ufshcd-qcom 1da4000.ufshc: ufshcd_get_max_pwr_mode:
invalid max pwm tx gear read = 0
[ÂÂÂ 6.983306] ufshcd-qcom 1da4000.ufshc: ufshcd_probe_hba: Failed
getting max supported power mode
[ÂÂÂ 8.506314] ufshcd-qcom 1da4000.ufshc: ufshcd_query_flag:
Sending flag query for idn 3 failed, err = -11
[ÂÂ 10.010352] ufshcd-qcom 1da4000.ufshc: ufshcd_query_flag:
Sending flag query for idn 3 failed, err = -11
[ÂÂ 11.514313] ufshcd-qcom 1da4000.ufshc: ufshcd_query_flag:
Sending flag query for idn 3 failed, err = -11
[ÂÂ 11.514412] ufshcd-qcom 1da4000.ufshc: ufshcd_query_flag_retry:
query attribute, opcode 5, idn 3, failed with error -11 after 3
retires
[ÂÂ 13.050354] ufshcd-qcom 1da4000.ufshc:
__ufshcd_query_descriptor: opcode 0x01 for idn 8 failed, index 0,
err = -11
[ÂÂ 14.554313] ufshcd-qcom 1da4000.ufshc:
__ufshcd_query_descriptor: opcode 0x01 for idn 8 failed, index 0,
err = -11
[ÂÂ 16.058313] ufshcd-qcom 1da4000.ufshc:
__ufshcd_query_descriptor: opcode 0x01 for idn 8 failed, index 0,
err = -11
[ÂÂ 16.058421] ufshcd-qcom 1da4000.ufshc: ufshcd_read_desc_param:
Failed reading descriptor. desc_id 8, desc_index 0, param_offset 0,
ret -11
[ÂÂ 16.067654] ufshcd-qcom 1da4000.ufshc: ufshcd_init_icc_levels:
Failed reading power descriptor.len = 98 ret = -11
[ÂÂ 37.074334] ufshcd-qcom 1da4000.ufshc: link startup failed 1
Can you check if your UFS device RESET_N is asserted correctly. It
might
be connected to some regulator and may be you can try keeping that
regulator as "regulator-always-on" from your DT node.
How do I check RESET_N? In software or hardware?
RST_N is the reset logic for UFS device core logic and it is input to
the device from UFS host controller.So, in your platform please
check if
this line somehow connected to (pulled up) a PMIC supply. If that is
the
case, please keep that regulator ON and see if this issue is resolved.
The reset line is routed though the global clock controller (GCC), and
must be explicitly asserted within the GCC to trigger a reset. As far
as I am aware, Linux is not touching this.
Additionally, I fail to see how if this was a reset issue, reverting
60f0187031c0 would have any impact (which doing so addresses our issue)
OK, that's again implementation dependent and your platform used that
way. My point was to make sure that reset part is ok, if reset/power is
not proper to the UFS device core logic this kind of issues comes.
We are following the Hardware Programming Guide written by the platform
designers with regard to UFS, including the reset logic. I really don't
think the reset logic is an issue here.
Do you think it is not a good idea to revert
60f0187031c05e04cbadffb62f557d0ff3564490 ?
Please hold on till we understand the real cause of this issue. Or we
have a consensuses for reverting the said commit.
Thanks!
Did you see https://lkml.org/lkml/2019/2/5/659 where I indicated VCCQ
powers components within the host controller, and by not setting load on
the regulator properly, we are likely undervolting those components due
to the current draw?
In theory may be true. But looks like we dont have a solid evidence yet
(correct me if I am wrong or misunderstood anything here
The evidence seems simple. We have properly described in DT all the
regulators that are consumed by the UFS host controller, and by
extension, the UFS storage chip as well.
By default, with no kernel changes, UFS does not work.
Marc and I debugged the issue, and found that the VCCQ regulator was not
being handled properly, and reverting the change we are discussing fixes
the the VCCQ regulator issue, and as a result UFS works.
Ok, fair, before we revert this patch, Marc can you try below patch, or
let me know if you have already tried this and share your
result/observation:
diff --git a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
index 50e9033aa7f6..b08e8d1ea0f3 100644
--- a/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8998-mtp.dtsi
@@ -212,6 +212,7 @@
vreg_l26a_1p2: l26 {
regulator-min-microvolt = <1200000>;
regulator-max-microvolt = <1200000>;
+ regulator-always-on;
};
vreg_l28_3p0: l28 {
regulator-min-microvolt = <3008000>;
---
I believe "vreg_l26a_1p2" is supply for ufs's vccq.
check the result of this patch /wo reverting
60f0187031c05e04cbadffb62f557d0ff3564490
Again, despite the fact that we may have a Samsung UFS storage chip,
which triggers the quirk, the UFS host controller which talks to that
chip requires VCCQ, therefore this quirk breaks us.
So that means its some short of hardware/board quirk, right?
No
Can you please recheck the schematic and see what Bjorn is telling
(about having right entries in the DT for regulator) resolve your issue?
Already done. The schematic defines vcc, vccq, and vccq2. All of those
are listed in DT, and have been since Marc and I have been trying to
utilize UFS.
Marc, Can you disabled pmic on that board (hope your board boots with
default PMIC supply) and see if this issue still occurs?
The PMIC is required the boot the board. I doubt the board will be
functional with the PMIC disabled.
I am just trying to understand and see what is the real cause.
Our analysis is that VCCQ is required and
60f0187031c05e04cbadffb62f557d0ff3564490 prevents the proper
configuration of VCCQ, thus a required resource (VCCQ) is not in the
proper state.
Not in proper state or vccq regulator is disabled?
Proper state. The PHY also consumes VCCQ, so it should be on, however
the regulators have multiple power savings states based on the amount of
load expressed. The amount of load the PHY puts on the regulator is
minimal. The load the controller puts on the regulator is significant
(which would result in a non-default state that would consume more
power), however the quirk prevents that load from being expressed, and
thus the regulator is in the wrong state for the system needs.
@Yaniv Gardi, will you be able to comment on reason for adding
60f0187031c05e04cbadffb62f557d0ff3564490 (any issue faced)?
--
Jeffrey Hugo
Qualcomm Datacenter Technologies as an affiliate of Qualcomm
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.