scsi: ufs: ufs-qcom: Fixup PAM-4 TX L0_L1_L2_L3 adaptation pattern length

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If HS-G6 Power Mode change handshake is successful and outbound data Lanes
are expected to transmit ADAPT, M-TX Lanes shall be configured as

  if (Adapt Type == REFRESH)
    TX_HS_ADAPT_LENGTH_L0_L1_L2_L3 = PA_PeerRxHsG6AdaptRefreshL0L1L2L3.
  else if (Adapt Type == INITIAL)
    TX_HS_ADAPT_LENGTH_L0_L1_L2_L3 = PA_PeerRxHsG6AdaptInitialL0L1L2L3.

On some platforms, the ADAPT_L0_L1_L2_L3 duration on Host TX Lanes is only
a half of theoretical ADAPT_L0_L1_L2_L3 duration TADAPT_L0_L1_L2_L3 (in
PAM-4 UI) calculated from TX_HS_ADAPT_LENGTH_L0_L1_L2_L3.

For such platforms, the workaround is to double the ADAPT_L0_L1_L2_L3
duration by uplifting TX_HS_ADAPT_LENGTH_L0_L1_L2_L3. UniPro initializes
TX_HS_ADAPT_LENGTH_L0_L1_L2_L3 during HS-G6 Power Mode change handshake, it
would be too late for SW to update TX_HS_ADAPT_LENGTH_L0_L1_L2_L3 post
HS-G6 Power Mode change. Update PA_PeerRxHsG6AdaptRefreshL0L1L2L3 and
PA_PeerRxHsG6AdaptInitialL0L1L2L3 post Link Startup and before HS-G6 Power
Mode change, so that the UniPro would use the updated value during HS-G6
Power Mode change handshake.

Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Can Guo <can.guo@oss.qualcomm.com>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Link: https://patch.msgid.link/20260325152154.1604082-9-can.guo@oss.qualcomm.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

...

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Can Guo 2026-03-25 08:21:50 -07:00 • committed by Martin K. Petersen

parent adbabdcf0d

commit 53c94067ef

1 changed files with 178 additions and 0 deletions

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drivers/ufs/host/ufs-qcom.c

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