[PATCH 1/5] mtd: rawnand: mtk: Correct low level time calculation of r/w cycle

xiaolei li xiaolei.li at mediatek.com
Mon Apr 29 17:59:42 PDT 2019


On Mon, 2019-04-29 at 12:02 +0200, Miquel Raynal wrote:
> Hi xiaolei,
> 
> xiaolei li <xiaolei.li at mediatek.com> wrote on Mon, 29 Apr 2019 17:35:53
> +0800:
> 
> > Hi Miquel,
> > 
> > Thanks for your review.
> > 
> > 
> > On Mon, 2019-04-29 at 11:03 +0200, Miquel Raynal wrote:
> > > Hi Xiaolei,
> > > 
> > > Xiaolei Li <xiaolei.li at mediatek.com> wrote on Mon, 29 Apr 2019 14:38:30
> > > +0800:
> > >   
> > > > At present, the flow of calculating AC timing of read/write cycle in SDR
> > > > mode is that:
> > > > At first, calculate high hold time which is valid for both read and write
> > > > cycle using the max value between tREH_min and tWH_min.
> > > > Secondly, calculate WE# pulse width using tWP_min.
> > > > Thridly, calculate RE# pulse width using the bigger one between tREA_max
> > > > and tRP_min.
> > > > 
> > > > But NAND SPEC shows that Controller should also meet write/read cycle time.
> > > > That is write cycle time should be more than tWC_min and read cycle should
> > > > be more than tRC_min. Obviously, we do not achieve that now.
> > > > 
> > > > This patch corrects the low level time calculation to meet minimum
> > > > read/write cycle time required. After getting the high hold time, WE# low
> > > > level time will be promised to meet tWP_min and tWC_min requirement,
> > > > and RE# low level time will be promised to meet tREA_max, tRP_min and
> > > > tRC_min requirement.
> > > > 
> > > > Fixes: 93db446a424c ("mtd: nand: move raw NAND related code to the raw/ subdir")  
> > > 
> > > This is definitely not the faulty patch. Please use --follow when
> > > searching for the culprit, to avoid being blocked by the
> > > renaming/moving work.  
> > Yes. This issue exists before raw/ sudir being created.
> > 
> > The faulty patch should be 'commit edfee3619c49 ("mtd: nand: mtk: add
> > ->setup_data_interface() hook")' which cannot be found in git history  
> > now.
> > 
> > Should I list it here?
> 
> What do you mean? This commit exists, I can actually "git show" it.
> 
Sorry. I find it. Will fix it in next patch version.
Thanks.

> 
> Thanks,
> Miquèl





More information about the linux-mtd mailing list