linux.git/include/ufs, branch v7.2-rc1

Merge branch 7.1/scsi-fixes into 7.2/scsi-staging

2026-06-16T01:01:30+00:00

Pull in outstanding commits from 7.1 branch.

Signed-off-by: Martin K. Petersen

scsi: ufs: core: Handle PM commands timeout before SCSI EH

2026-06-08T21:41:45+00:00

A PM START STOP sent from the UFS well-known LU resume path can race
with SCSI EH:

The "wl resume" task flow is:
  __ufshcd_wl_resume()
    ufshcd_set_dev_pwr_mode(UFS_ACTIVE_PWR_MODE)
      ufshcd_execute_start_stop()
        scsi_execute_cmd()
          blk_execute_rq           <-- wait
          scsi_check_passthrough() <-- may retry START STOP

If the first START STOP time out, SCSI EH may already recover the link and
reset the device before scsi_execute_cmd() returns:

  scsi_timeout()
    scsi_eh_scmd_add()
      scsi_error_handler()
        scsi_unjam_host()
          scsi_eh_ready_devs()
            scsi_eh_host_reset()
              ufshcd_eh_host_reset_handler()
                if (hba->pm_op_in_progress)
                  ufshcd_link_recovery()
                    ufshcd_device_reset()
                    ufshcd_host_reset_and_restore()
          ...
          scsi_eh_flush_done_q()   <-- wakeup "wl resume" task
        ...                        <-- host still in SHOST_RECOVERY
        scsi_restart_operations()

A later passthrough retry can then run while the host is still in
SHOST_RECOVERY and hit the SCMD_FAIL_IF_RECOVERING path:

  scsi_queue_rq()
    if (scsi_host_in_recovery(shost) &&
        cmd->flags & SCMD_FAIL_IF_RECOVERING)
      return BLK_STS_OFFLINE

That retry completes with DID_ERROR or DID_NO_CONNECT even though EH may
already have restored the device to an operational ACTIVE state.

Handle these PM timeouts directly from ufshcd_eh_timed_out() instead.
After ufshcd_link_recovery(), complete the timed-out command immediately
if it has not been completed already.

For regular SCSI commands, complete them with DID_REQUEUE to match the
existing MCQ force-completion semantics and allow scsi_execute_cmd() to
retry if needed. For reserved internal device-management commands,
finish the request with DID_TIME_OUT without calling
ufshcd_release_scsi_cmd() since those commands use different resource
lifetime rules.

The system_suspending flag is no longer needed because PM command
timeout handling now uses pm_op_in_progress.

Fixes: b8c3a7bac9b6 ("scsi: ufs: Have midlayer retry start stop errors")
Signed-off-by: Hongjie Fang 
Reviewed-by: Bart Van Assche 
Reviewed-by: Peter Wang 
Link: https://patch.msgid.link/20260605112034.3802540-1-hongjiefang@asrmicro.com
Signed-off-by: Martin K. Petersen

scsi: ufs: core: Add a quirk for extended TX EQTR Adapt L0L1L2L3 length

2026-05-23T01:14:59+00:00

Add a quirk to support TX Equalization Training (EQTR) using Adapt
L0L1L2L3 length which is larger than what is allowed by M-PHY spec ver
6.0.

Signed-off-by: Can Guo 
Reviewed-by: Bean Huo 
Reviewed-by: Bart Van Assche 
Reviewed-by: Peter Wang 
Reviewed-by: Ziqi Chen 
Link: https://patch.msgid.link/20260501131641.826258-2-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen

scsi: ufs: core: Add support to retrieve and store TX Equalization settings

2026-05-05T07:27:42+00:00

Add support for UFS v5.0 JEDEC attributes qTxEQGnSettings and
wTxEQGnSettingsExt to enable persistent storage and retrieval of
optimal TX Equalization settings.

This provides a fast-path for TX Equalization by reusing previously
stored optimal settings, avoiding TX Equalization Training (EQTR)
procedures during subsequent Power Mode changes.

When no valid TX Equalization settings are found, fall back to full TX
EQTR procedures and optionally save the results for future use.

The validity of one set of TX Equalization settings is indicated by
Bit[15] in wTxEQGnSettingsExt.

Signed-off-by: Can Guo 
Reviewed-by: Peter Wang 
Reviewed-by: Bean Huo 
Reviewed-by: Bart Van Assche 
Link: https://patch.msgid.link/20260424151420.111675-3-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen

scsi: ufs: core: Fix bRefClkFreq write failure in HS-LSS mode

2026-04-22T00:58:06+00:00

According to the UFS spec, the bRefClkFreq attribute can only be written
when both sub-links are in LS-MODE. However, in HS LSS mode with
resetmode = HS_MODE, if the UFS device's default bRefClkFreq value
differs from the host controller's dev_ref_clk_freq setting, the write
operation will fail.

To fix this issue, introduce ufshcd_get_op_mode() function to detect the
current link operational mode. Call ufshcd_set_dev_ref_clk() only when
both sub-links are in LS-MODE to ensure the attribute can be written
successfully.

Signed-off-by: Wang Shuaiwei 
Link: https://patch.msgid.link/20260414033718.1459540-1-wangshuaiwei1@xiaomi.com
Reviewed-by: Peter Wang 
Signed-off-by: Martin K. Petersen

Merge patch series "scsi: ufs: Add TX Equalization support for UFS 5.0"

2026-03-27T21:21:28+00:00

Can Guo  says:

Hi,

The UFS v5.0 and UFSHCI v5.0 standards have published, introducing support
for HS-G6 (46.6 Gbps per lane) through the new UniPro V3.0 interconnect
layer and M-PHY V6.0 physical layer specifications. To achieve reliable
operation at these higher speeds, UniPro V3.0 introduces TX Equalization
and Pre-Coding mechanisms that are essential for signal integrity.

This patch series implements TX Equalization support in the UFS core
driver as specified in UFSHCI v5.0, along with the necessary vendor
operations and a reference implementation for Qualcomm UFS host
controllers.

Background
==========

TX Equalization is a signal conditioning technique that compensates for
channel impairments at high data rates (HS-G4 through HS-G6). It works
by adjusting two key parameters:

- PreShoot: Pre-emphasis applied before the main signal transition
- DeEmphasis: De-emphasis applied after the main signal transition

UniPro V3.0 defines TX Equalization Training (EQTR) procedure to
automatically discover optimal TX Equalization settings. The EQTR
procedure:

1. Starts from the most reliable link state (HS-G1)
2. Iterates through all possible PreShoot and DeEmphasis combinations
3. Evaluates signal quality using Figure of Merit (FOM) measurements
4. Selects the best settings for both host and device TX lanes

For HS-G6, Pre-Coding is also introduced to further improve signal
quality. Pre-Coding must be enabled on both transmitter and receiver
when the RX_FOM indicates it is required.

Implementation Overview
=======================

The implementation follows the UFSHCI v5.0 specification and consists of:

Core Infrastructure (Patches 1-6):
- New vops callback negotiate_pwr_mode() to allow vendors to negotiate
  power mode parameters before applying TX Equalization settings
- Support for HS-G6 gear enumeration
- Complete TX EQTR procedure implementation in ufs-txeq.c
- Debugfs interface for TX Equalization parameter inspection and manual
  retraining
- Module parameters for adaptive TX Equalization control

Qualcomm Implementation (Patches 7-11):
- PHY-specific configurations for TX EQTR procedure
- Vendor-specific FOM measurement support
- TX Equalization settings application
- Enable TX Equalization for HW version 0x7 and onwards

The implementation is designed to be vendor-agnostic, with platform-
specific details handled through the vops callbacks. Other vendors can
add support by implementing the three new vops:

- tx_eqtr_notify(): Called before/after TX EQTR for vendor setup
- apply_tx_eqtr_settings(): Apply vendor-specific PHY configurations
- get_rx_fom(): Retrieve vendor-specific FOM measurements if needed

Module Parameters
=================

The implementation provides several module parameters for flexibility:

- use_adaptive_txeq: Enable/disable adaptive TX Equalization (default: false)
- adaptive_txeq_gear: Minimum gear for adaptive TX EQ (default: HS-G6)
- use_txeq_presets: Use only the 8 standaird presets (default: false)
- txeq_presets_selected[]: Select specific presets for EQTR

Testing
=======

This patch series has been tested on Qualcomm platforms with UFS 5.0
devices, validating:

- Successful TX EQTR completion for HS-G6
- Proper FOM evaluation and optimal settings selection
- Pre-Coding enablement for HS-G6
- Power mode changes with TX Equalization settings applied
- Report of TX Equalization settings via debugfs entries
- Report of TX EQTR histories via debug entries (see next section)
- Re-training TX Equalization via debugfs entry

Example of TX EQTR history
==========================

Device TX EQTR record summary -
Target Power Mode: HS-G6, Rate-B
Most recent record index: 2
Most recent record timestamp: 219573378 us

TX Lane 0 FOM - PreShoot\DeEmphasis
\       0        1        2        3        4        5        6        7
0      50       70       65        -        -        -        -        x
1       x        x        x        x        x        x        x        x
2     100       90       70        -        -        -        -        x
3       x        x        x        x        x        x        x        x
4      95       90        -        -        -        -        -        x
5       -        -        -        -        -        -        -        x
6       x        x        x        x        x        x        x        x
7       x        x        x        x        x        x        x        x

TX Lane 1 FOM - PreShoot\DeEmphasis
\       0        1        2        3        4        5        6        7
0      50       70       60        -        -        -        -        x
1       x        x        x        x        x        x        x        x
2     100       80       65        -        -        -        -        x
3       x        x        x        x        x        x        x        x
4      95       85        -        -        -        -        -        x
5       -        -        -        -        -        -        -        x
6       x        x        x        x        x        x        x        x
7       x        x        x        x        x        x        x        x

Patch Structure
===============

Patches 1-3: Preparatory changes for power mode negotiation and HS-G6
Patch 4: Core TX Equalization and EQTR implementation
Patches 5-7: Debugfs support for TX Equalization
Patches 8-12: Qualcomm vendor implementation

Next
====

One more series has been developed to enhance TX Equalization support,
which will be submitted for review after this series is accepted:

- Provide board specific (static) TX Equalization settings from DTS
- Parse static TX Equalization settings from DTS if provided
- Apply static TX Equalization settings if use_adaptive_txeq is disabled
- Add support for UFS v5.0 attributes qTxEQGnSettings & wTxEQGnSettingsExt
- Enable persistent storage and retrieval of optimal TX Equalization settings

Link: https://patch.msgid.link/20260325152154.1604082-1-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen

scsi: ufs: ufs-qcom: Implement vops get_rx_fom()

2026-03-27T21:20:30+00:00

On some platforms, host's M-PHY RX_FOM Attribute always reads 0, meaning SW
cannot rely on Figure of Merit (FOM) to identify the optimal TX
Equalization settings for device's TX Lanes. Implement the vops
ufs_qcom_get_rx_fom() such that SW can utilize the UFS Eye Opening Monitor
(EOM) to evaluate the TX Equalization settings for device's TX Lanes.

Reviewed-by: Bean Huo 
Reviewed-by: Bart Van Assche 
Signed-off-by: Can Guo 
Reviewed-by: Peter Wang 
Link: https://patch.msgid.link/20260325152154.1604082-11-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen

scsi: ufs: core: Add support to retrain TX Equalization via debugfs

2026-03-27T21:20:30+00:00

Drastic environmental changes, such as significant temperature shifts, can
impact link signal integrity. In such cases, retraining TX Equalization is
necessary to compensate for these environmental changes.

Add a debugfs entry, 'tx_eq_ctrl', to allow userspace to manually trigger
the TX Equalization training (EQTR) procedure and apply the identified
optimal settings on the fly. These entries are created on a per-gear basis
for High Speed Gear 4 (HS-G4) and above, as TX EQTR is not supported for
lower gears.

The 'tx_eq_ctrl' entry currently accepts the 'retrain' command to initiate
the procedure. The interface is designed to be scalable to support
additional commands in the future.

Reading the 'tx_eq_ctrl' entry provides a usage hint to the user, ensuring
the interface is self-documenting.

The ufshcd's debugfs folder structure will look like below:

  /sys/kernel/debug/ufshcd/*ufs*/
  |--tx_eq_hs_gear1/
  |  |--device_tx_eq_params
  |  |--host_tx_eq_params
  |--tx_eq_hs_gear2/
  |--tx_eq_hs_gear3/
  |--tx_eq_hs_gear4/
  |--tx_eq_hs_gear5/
  |--tx_eq_hs_gear6/
     |--device_tx_eq_params
     |--device_tx_eqtr_record
     |--host_tx_eq_params
     |--host_tx_eqtr_record
     |--tx_eq_ctrl

Reviewed-by: Bean Huo 
Reviewed-by: Bart Van Assche 
Signed-off-by: Can Guo 
Reviewed-by: Peter Wang 
Link: https://patch.msgid.link/20260325152154.1604082-8-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen

scsi: ufs: core: Add support for TX Equalization

2026-03-27T21:20:29+00:00

MIPI Unipro3.0 introduced PA_TxEQGnSetting and PA_PreCodeEn attributes for
TX Equalization and Pre-Coding. It is Host Software's responsibility to
configure these attributes for both host and device before initiating Power
Mode Change to High-Speed Gears.

MIPI Unipro3.0 also introduced TX Equalization Training (EQTR) to identify
optimal TX Equalization settings for use by both Host's and Device's
UniPro. TX EQTR shall be initiated from the most reliable High-Speed Gear
(HS-G1) targeting High-Speed Gears (HS-G4 to HS-G6).

Implement TX Equalization configuration and TX EQTR procedure as defined
in UFSHCI v5.0 specification. The TX EQTR procedure determines the optimal
TX Equalization settings by iterating through all possible PreShoot and
DeEmphasis combinations and selecting the best combinations for both Host
and Device based on Figure of Merit (FOM) evaluation.

Reviewed-by: Bean Huo 
Reviewed-by: Bart Van Assche 
Signed-off-by: Can Guo 
Reviewed-by: Peter Wang 
Link: https://patch.msgid.link/20260325152154.1604082-5-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen

scsi: ufs: core: Add UFS_HS_G6 and UFS_HS_GEAR_MAX to enum ufs_hs_gear_tag

2026-03-27T21:20:29+00:00

Add UFS_HS_G6 to enum ufs_hs_gear_tag. In addition, add UFS_HS_GEAR_MAX to
enum ufs_hs_gear_tag to facilitate iteration over valid High Speed Gears.

Reviewed-by: Bart Van Assche 
Reviewed-by: Bean Huo 
Signed-off-by: Can Guo 
Reviewed-by: Peter Wang 
Link: https://patch.msgid.link/20260325152154.1604082-4-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen