Messages in this thread | | | Subject | Re: [PATCH v2 0/2] mtd: nand: wait for tWHR, and fix the setup_data_interface of Denali | From | Marc Gonzalez <> | Date | Wed, 4 Oct 2017 13:05:11 +0200 |
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On 29/09/2017 16:33, Masahiro Yamada wrote:
> (+CC Marc Gonzalez) > > 2017-09-29 21:26 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>: >> On Fri, 29 Sep 2017 19:38:38 +0900 >> Masahiro Yamada <yamada.masahiro@socionext.com> wrote: >> >>> 1/2 : add NAND_WAIT_TWHR and nand_whr_delay(). >>> You can set this new flag if you want nand_command(_lp) >>> to insert tWHR delay where needed. >>> >>> 2/2 : Fix Denali setup_data_interface. >>> Boris' suggestion in v1 was a good reminder that >>> made me realize tCCS was missing in the driver. Fix it now. >>> >>> >>> Changes in v2: >>> - Add nand_whr_delay() helper >>> Wait for tWHR only for drivers that explicitly set NAND_WAIT_TWHR flag >>> - newly added >>> >>> Masahiro Yamada (2): >>> mtd: nand: wait for tWHR after NAND_CMD_STATUS / NAND_CMD_READID >> >> Hm, I thought you were introducing this to then use it in the denali >> driver. Sorry, but I don't want to apply something that nobody needs. >> If someone ever complains about a missing delay I'll point him to your >> patch, but until then I'll keep the core unchanged. > > Perhaps, Marc Gonzalez is the person. > > > tango_nand.c is the only driver that sets NAND_WAIT_TCCS. > > Now, there is completely no delay when reading out the ID. > > > One safe change might be apply this patch, > then set NAND_WAIT_TWHR to tango_nand.c > > > I am guessing NAND_WAIT_TCCS was added for it. > Theoretically, I do not see logical difference between tCCS and tWHR. > > I am CCing Marc Gonzalez, the author of tango_nand.c
Hello Masahiro,
I remember having issues reading the ONFI ID when I was writing the driver, a year ago. Sometimes, the first few bytes appeared to be missing. This looked like a timing issue.
Adding the dev_ready call-back solved the problem. Do you think that was by accident? When I have more time, I will test the 4.14 branch, to see if there are any issues with the current driver.
Regards.
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