RE: [PATCH v2 1/5] scsi: ufs: allow legacy UFS devices to enable WriteBooster

From: Avri Altman
Date: Thu Apr 30 2020 - 03:44:49 EST


Hi Stanley,

>
> WriteBooster feature may be supported by some legacy UFS devices
> (i.e., < 3.1) by upgrading firmware.
>
> To enable WriteBooster feature in such devices, relax the entrance
> condition of ufshcd_wb_probe() to allow host driver to check those
> devices' WriteBooster capability.
>
> WriteBooster feature can be available if below both conditions are
> satisfied,
>
> 1. Device descriptor has dExtendedUFSFeaturesSupport field.
> 2. WriteBooster support is specified in above field.
>
> Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>
WB was first introduced as part of UFS3.1, and lately as part of UFS2.2.
Any non-standard behavior should be classified as a quirk.

Thanks,
Avri