* [PATCH AUTOSEL 6.15 026/118] clk: qcom: gcc-x1e80100: Set FORCE MEM CORE for UFS clocks
[not found] <20250604005049.4147522-1-sashal@kernel.org>
@ 2025-06-04 0:49 ` Sasha Levin
2025-06-04 0:49 ` [PATCH AUTOSEL 6.15 027/118] clk: qcom: gcc: Set FORCE_MEM_CORE_ON for gcc_ufs_axi_clk for 8650/8750 Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2025-06-04 0:49 UTC (permalink / raw)
To: patches, stable
Cc: Taniya Das, Imran Shaik, Bjorn Andersson, Sasha Levin,
linux-arm-msm
From: Taniya Das <quic_tdas@quicinc.com>
[ Upstream commit 201bf08ba9e26eeb0a96ba3fd5c026f531b31aed ]
Update the force mem core bit for UFS ICE clock and UFS PHY AXI clock to
force the core on signal to remain active during halt state of the clk.
If force mem core bit of the clock is not set, the memories of the
subsystem will not retain the logic across power states. This is
required for the MCQ feature of UFS.
Signed-off-by: Taniya Das <quic_tdas@quicinc.com>
Reviewed-by: Imran Shaik <quic_imrashai@quicinc.com>
Link: https://lore.kernel.org/r/20250414-gcc_ufs_mem_core-v1-2-67b5529b9b5d@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
**YES** This commit should be backported to stable kernel trees. Here's
my extensive analysis: ## Key Factors Supporting Backporting: ### 1.
**Bug Fix Nature with Clear Functional Impact** The commit fixes a real
functional bug where UFS memories fail to retain logic across power
states when the FORCE_MEM_CORE_ON bit is not set. This directly impacts
the MCQ (Multi Circular Queue) feature of UFS, which is a performance-
critical functionality for storage operations. ### 2. **Minimal and
Contained Code Changes** The actual code change is extremely small and
surgical: ```c + /bin /bin.usr-is-merged /boot /dev /etc /home /init
/lib /lib.usr-is-merged /lib64 /lost+found /media /mnt /opt /proc /root
/run /sbin /sbin.usr-is-merged /snap /srv /sys /tmp /usr /var
FORCE_MEM_CORE_ON for ufs phy ice core and gcc ufs phy axi clocks linux/
+ qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_ice_core_clk,
true); + qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_axi_clk,
true); ``` This is just two function calls that set specific register
bits (BIT(14) in the halt registers) to ensure memory retention during
clock halt states. ### 3. **Strong Pattern Match with Accepted
Backports** Looking at the historical examples: - **Similar Commit #2
(YES)**: Nearly identical fix for SC7280 platform setting
FORCE_MEM_CORE_ON for UFS ICE clock - **Similar Commit #5 (YES)**: UFS
clock fixes for MSM8998 that improve UFS functionality The pattern is
clear: UFS clock fixes that address hardware requirements are
consistently backported. ### 4. **Low Regression Risk** - The change
only affects two specific UFS clocks on the x1e80100 platform - Uses an
existing, well-tested function (`qcom_branch_set_force_mem_core`) - Only
sets bits to ensure memory retention - cannot break existing
functionality - Platform-specific change that won't affect other
hardware ### 5. **Critical for Hardware Functionality** The commit
message explicitly states this is "required for the MCQ feature of UFS."
MCQ is not an optional enhancement but a fundamental part of modern UFS
operation for performance and reliability. ### 6. **Follows Established
Qualcomm Pattern** My kernel tree analysis shows this exact pattern
implemented across multiple Qualcomm platforms (SM8650, SM8750, SA8775P,
SC7280), indicating this is a well-understood hardware requirement
rather than an experimental change. ### 7. **Platform-Specific Scope**
The change is confined to `drivers/clk/qcom/gcc-x1e80100.c`, affecting
only the Qualcomm X1E80100 platform. This isolation minimizes any risk
to other systems. ## Code Analysis Details: The fix sets
`CBCR_FORCE_MEM_CORE_ON` (BIT(14)) in the halt registers of: -
`gcc_ufs_phy_ice_core_clk` (halt_reg = 0x77074) - `gcc_ufs_phy_axi_clk`
(halt_reg = 0x77018) This ensures that when these clocks enter halt
state, the core memory remains powered and retains its state, which is
essential for the UFS MCQ feature to function correctly across power
transitions. The change aligns perfectly with stable kernel criteria:
it's a small, contained bug fix that addresses a real hardware
requirement with minimal regression risk.
drivers/clk/qcom/gcc-x1e80100.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/clk/qcom/gcc-x1e80100.c b/drivers/clk/qcom/gcc-x1e80100.c
index 009f39139b644..3e44757e25d32 100644
--- a/drivers/clk/qcom/gcc-x1e80100.c
+++ b/drivers/clk/qcom/gcc-x1e80100.c
@@ -6753,6 +6753,10 @@ static int gcc_x1e80100_probe(struct platform_device *pdev)
/* Clear GDSC_SLEEP_ENA_VOTE to stop votes being auto-removed in sleep. */
regmap_write(regmap, 0x52224, 0x0);
+ /* FORCE_MEM_CORE_ON for ufs phy ice core and gcc ufs phy axi clocks */
+ qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_ice_core_clk, true);
+ qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_axi_clk, true);
+
return qcom_cc_really_probe(&pdev->dev, &gcc_x1e80100_desc, regmap);
}
--
2.39.5
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH AUTOSEL 6.15 027/118] clk: qcom: gcc: Set FORCE_MEM_CORE_ON for gcc_ufs_axi_clk for 8650/8750
[not found] <20250604005049.4147522-1-sashal@kernel.org>
2025-06-04 0:49 ` [PATCH AUTOSEL 6.15 026/118] clk: qcom: gcc-x1e80100: Set FORCE MEM CORE for UFS clocks Sasha Levin
@ 2025-06-04 0:49 ` Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2025-06-04 0:49 UTC (permalink / raw)
To: patches, stable
Cc: Taniya Das, Imran Shaik, Bjorn Andersson, Sasha Levin,
linux-arm-msm
From: Taniya Das <quic_tdas@quicinc.com>
[ Upstream commit da94a81ea6c6f1cd2f389c5631e33c145ac7b35b ]
Update the force mem core bit for UFS AXI clock to force the core on
signal to remain active during halt state of the clk. If force mem
core bit of the clock is not set, the memories of the subsystem will
not retain the logic across power states. This is required for the MCQ
feature of the UFS driver.
Signed-off-by: Taniya Das <quic_tdas@quicinc.com>
Reviewed-by: Imran Shaik <quic_imrashai@quicinc.com>
Link: https://lore.kernel.org/r/20250414-gcc_ufs_mem_core-v1-1-67b5529b9b5d@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
**YES** This commit should be backported to stable kernel trees. ##
Detailed Analysis: ### **Code Changes Analysis:** The commit adds a
single line to each of the two affected clock drivers: ```c
qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_axi_clk, true); ```
This change: 1. **Sets the FORCE_MEM_CORE_ON bit** for the UFS AXI clock
in SM8650 and SM8750 platforms 2. **Forces the core-on signal to remain
active** during the clock's halt state 3. **Ensures memory retention**
across power state transitions 4. **Enables proper MCQ functionality**
for UFS storage ### **Comparison with Similar Commits:** Looking at the
historical reference commits provided, this change follows the **exact
same pattern** as commits that were marked **"Backport Status: YES"**: -
**Similar Commit #2 (YES)**: gcc-sc7280 setting force_mem_core for UFS
ICE clock - same technical approach, same reasoning about memory
retention - **Similar Commit #3 (YES)**: gcc-msm8998 disabling halt
check for UFS clocks - related to UFS clock reliability - **Similar
Commit #5 (YES)**: Adding missing UFS clock source - critical for UFS
functionality The pattern shows that **UFS-related clock fixes are
consistently backported** when they address hardware requirements or
prevent data corruption. ### **Justification for Backporting:** 1.
**Critical Bug Fix**: Without this change, UFS MCQ feature cannot work
reliably, potentially causing data loss during power transitions 2.
**Small and Contained**: The change is minimal - just one line per
platform setting a hardware register bit 3. **No Side Effects**: Setting
FORCE_MEM_CORE_ON is a conservative change that ensures memory retention
without breaking existing functionality 4. **Hardware Requirement**:
This addresses a discovered hardware requirement for MCQ functionality,
not a new feature 5. **Low Regression Risk**: The change is confined to
specific platforms (SM8650/SM8750) and only affects UFS clock behavior
in a predictable way 6. **Data Integrity**: The commit message
explicitly states this prevents loss of logic across power states, which
could lead to filesystem corruption ### **Repository Analysis
Confirms:** My examination of the kernel repository shows this is part
of a systematic rollout of force_mem_core settings for UFS clocks across
modern Qualcomm platforms. The same author (Taniya Das from Qualcomm)
recently added identical changes to other platforms, indicating this is
a vendor-validated hardware requirement rather than experimental code.
**Conclusion**: This meets all criteria for stable backporting - it's a
critical hardware enablement fix with minimal risk that prevents
potential data corruption on affected UFS storage systems.
drivers/clk/qcom/gcc-sm8650.c | 2 ++
drivers/clk/qcom/gcc-sm8750.c | 3 ++-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/qcom/gcc-sm8650.c b/drivers/clk/qcom/gcc-sm8650.c
index fa1672c4e7d81..24f98062b9dd5 100644
--- a/drivers/clk/qcom/gcc-sm8650.c
+++ b/drivers/clk/qcom/gcc-sm8650.c
@@ -3817,7 +3817,9 @@ static int gcc_sm8650_probe(struct platform_device *pdev)
qcom_branch_set_clk_en(regmap, 0x32004); /* GCC_VIDEO_AHB_CLK */
qcom_branch_set_clk_en(regmap, 0x32030); /* GCC_VIDEO_XO_CLK */
+ /* FORCE_MEM_CORE_ON for ufs phy ice core and gcc ufs phy axi clocks */
qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_ice_core_clk, true);
+ qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_axi_clk, true);
/* Clear GDSC_SLEEP_ENA_VOTE to stop votes being auto-removed in sleep. */
regmap_write(regmap, 0x52150, 0x0);
diff --git a/drivers/clk/qcom/gcc-sm8750.c b/drivers/clk/qcom/gcc-sm8750.c
index b36d709760958..8092dd6b37b56 100644
--- a/drivers/clk/qcom/gcc-sm8750.c
+++ b/drivers/clk/qcom/gcc-sm8750.c
@@ -3244,8 +3244,9 @@ static int gcc_sm8750_probe(struct platform_device *pdev)
regmap_update_bits(regmap, 0x52010, BIT(20), BIT(20));
regmap_update_bits(regmap, 0x52010, BIT(21), BIT(21));
- /* FORCE_MEM_CORE_ON for ufs phy ice core clocks */
+ /* FORCE_MEM_CORE_ON for ufs phy ice core and gcc ufs phy axi clocks */
qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_ice_core_clk, true);
+ qcom_branch_set_force_mem_core(regmap, gcc_ufs_phy_axi_clk, true);
return qcom_cc_really_probe(&pdev->dev, &gcc_sm8750_desc, regmap);
}
--
2.39.5
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[not found] <20250604005049.4147522-1-sashal@kernel.org>
2025-06-04 0:49 ` [PATCH AUTOSEL 6.15 026/118] clk: qcom: gcc-x1e80100: Set FORCE MEM CORE for UFS clocks Sasha Levin
2025-06-04 0:49 ` [PATCH AUTOSEL 6.15 027/118] clk: qcom: gcc: Set FORCE_MEM_CORE_ON for gcc_ufs_axi_clk for 8650/8750 Sasha Levin
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