RE: [PATCH v1 1/3] scsi: ufs: add write booster feature support

[Avri Altman]

> 
> On Wed, Apr 8, 2020 at 3:00 PM Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> wrote:
> >
> > The write performance of TLC NAND is considerably
> > lower than SLC NAND. Using SLC NAND as a WriteBooster
> > Buffer enables the write request to be processed with
> > lower latency and improves the overall write performance.
> >
> > Adds support for shared-buffer mode WriteBooster.
> >
> > WriteBooster enable: SW enables it when clocks are
> > scaled up, thus it's enabled only in high load conditions.
> >
> > WriteBooster disable: SW will disable the feature,
> > when clocks are scaled down. Thus writes would go as normal
> > writes.
> 
> btw, in v5.8-rc1 (plus handful of remaining patches for lenovo c630
> laptop (sdm850)), I'm seeing a lot of:
> 
>   ufshcd-qcom 1d84000.ufshc: ufshcd_query_flag: Sending flag query for
> idn 14 failed, err = 253
>   ufshcd-qcom 1d84000.ufshc: ufshcd_query_flag: Sending flag query for
> idn 14 failed, err = 253
>   ufshcd-qcom 1d84000.ufshc: ufshcd_query_flag_retry: query attribute,
> opcode 6, idn 14, failed with error 253 after 3 retires
>   ufshcd-qcom 1d84000.ufshc: ufshcd_wb_ctrl write booster enable failed 253
> 
> and at least subjectively, compiling mesa seems slower, which seems
> like it might be related?
This looks like a device issue to be taken with the flash vendor:
The device reports that it supports wd, but returns inalid idn for flag 0xe...

Thanks,
Avri