[PATCH v1 02/10] ufs: host: mediatek: Add DDR_EN setting

[Peter Wang (王信友)]

On Wed, 2025-07-16 at 08:22 -0700, Bart Van Assche wrote:
> 
> External email : Please do not click links or open attachments until
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> 
> 
> On 7/15/25 11:25 PM, peter.wang at mediatek.com wrote:
> > On MT6989 and later platforms, control of DDR_EN has been switched
> > from
> > SPM to EMI. To prevent abnormal access to DRAM, it is necessary to
> > wait
> > for 'ddren_ack' or assert 'ddren_urgent' after sending 'ddren_req'.
> > 
> > This patch introduces the DDR_EN configuration in the UFS
> > initialization
> > flow, utilizing the assertion of 'ddren_urgent' to maintain
> > performance.
> 
> What is SPM? What is EMI? What is DDR_EN? Please expand these
> acronyms.
> 

Hi Bart,

Sorry, this is confidential to MediaTek’s design, as ufs-mediatek.c
is code specific to the MediaTek UFS host. It does not involve common
or other host usages, so please allow us not to explain the design
details or abbreviations.


> > +/* UFS MTK ip version value */
> > +enum {
> > +     /* UFS 3.1 */
> > +     IP_VER_MT6878    = 0x10420200,
> > +
> > +     /* UFS 4.0 */
> > +     IP_VER_MT6897    = 0x10440000,
> > +     IP_VER_MT6989    = 0x10450000,
> > +
> > +     IP_VER_NONE      = 0xFFFFFFFF
> > +};
> 
> How can MediaTek IP versions be related to the UFS standard? Should
> "UFS" perhaps be changed into "UFSHCI" in the above comments?
> 
> Thanks,
> 
> Bart.


Sure, I will update the comment from "UFS" to "UFSHCI".

Thanks.
Peter