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From: Can Guo <can.guo@oss.qualcomm.com>
To: Krzysztof Kozlowski <krzk@kernel.org>,
	bvanassche@acm.org, beanhuo@micron.com, peter.wang@mediatek.com,
	martin.petersen@oracle.com, mani@kernel.org
Cc: linux-scsi@vger.kernel.org, Alim Akhtar <alim.akhtar@samsung.com>,
	Avri Altman <avri.altman@wdc.com>, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Zhaoming Luo <zhml@posteo.com>,
	Ram Kumar Dwivedi <quic_rdwivedi@quicinc.com>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 1/2] dt-bindings: ufs: Document static TX Equalization settings properties
Date: Thu, 11 Jun 2026 22:14:06 +0800	[thread overview]
Message-ID: <ec582b2d-012f-4bba-a247-4b7040d02df9@oss.qualcomm.com> (raw)
In-Reply-To: <b62e7f1a-bc13-442c-ad7b-0969e3b9073d@kernel.org>



On 6/11/2026 9:32 PM, Krzysztof Kozlowski wrote:
> On 10/06/2026 09:15, Can Guo wrote:
>> UFS v5.0/UFSHCI v5.0 add HS-G6 support via UniPro v3.0 and M-PHY v6.0.
>> These specs define TX Equalization for all High Speed Gears, and HS-G6 may
>> also require TX precode depending on channel characteristics.
>>
>> Document vendor-neutral DT properties in ufs-common.yaml:
>>
>> - patternProperties for txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6]
>> - tx-precode-g6-host-lanes
>> - tx-precode-g6-device-lanes
>>
>> txeq-preshoot-g[1-6] and txeq-deemphasis-g[1-6] accept per-lane tuples:
>> <Host_Lane0 Device_Lane0>, [<Host_Lane1 Device_Lane1>]
> Instead of repeating the diff, you should explain why these properties
> are needed. Insufficient explanation was also pointed out at v1.
>
> Why this cannot be deduced from the IP compatible? Does it depend on the
> device memory? Who determines the values here and what do they depend
> on? Also here you explain lack of auto tuning for example.
I will give more explanations in next version.
>
>> PreShoot and DeEmphasis values are 0..7 and accept 2 or 4 values for x1/x2
>> lane configurations.
>>
> ...
>
>
>> +      Lane indices for static Host-side TX precode enable settings for HS-G6
>> +      only. Listed lanes have precode enabled; unlisted lanes are disabled.
>> +
>> +  tx-precode-g6-device-lanes:
>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>> +    minItems: 1
>> +    maxItems: 2
>> +    uniqueItems: true
>> +    items:
>> +      minimum: 0
>> +      maximum: 1
>> +    description: |
>> +      Lane indices for static Device-side TX precode enable settings for HS-G6
>> +      only. Listed lanes have precode enabled; unlisted lanes are disabled.
>
> I need to reverse my opinion and let's go to v6 implementation. These
> properties look more consistent in v6 with respect to preshoot and
> deepmhasis properties.
>
> You want actually matrix, so:
>
>    tx-precode-enable-g6:
>      $ref: /schemas/types.yaml#/definitions/uint32-matrix
>      oneOf:
>        - items:
>            - description: Host_Lane0 precode
>            - description: Device_Lane0 precode
>        - items:
>            - description: Host_Lane0 precode
>            - description: Device_Lane0 precode
>            - description: Host_Lane1 precode
>            - description: Device_Lane1 precode
>      items:
>        enum: [0, 1]
>      description:
>        Static TX Precode enable values for HS-G6 only.
>
> And similar style with items also for preshoot and deepmhasis.
Thanks for the suggestions. Will update in next version and come back.

Best Regards,
Can Guo.
>
>
> Best regards,
> Krzysztof


      reply	other threads:[~2026-06-11 14:14 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20260610071516.3763916-1-can.guo@oss.qualcomm.com>
2026-06-10  7:15 ` [PATCH v7 1/2] dt-bindings: ufs: Document static TX Equalization settings properties Can Guo
2026-06-11 13:32   ` Krzysztof Kozlowski
2026-06-11 14:14     ` Can Guo [this message]

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