Hi Jane, On Tue, 1 May 2018 05:01:23 +0000, "Wan, Jane (Nokia - US/Sunnyvale)" <[email protected]> wrote:
> Hi Miquèl and Boris, > > Thank you for your response and feedback. I've modified the fix based on > your comments. > Please see the updated patch file at the end of this message (also in > attachment). > My answers to your comments/questions are inline in the previous message. Usually we answer inline in each e-mail, then we post a new version with a version counter incremented (use the '-v2- of 'git format-patch' to add the '[PATCH v2 x/y]' prefix automatically). Reposting is important as maintainers use 'patchwork' to follow the evolution of each patch. So in your case, nothing shows that you posted a v2. > > Here is the answer to Boris question in another email thread: > > > What if some NANDs have 4 or more copies of the param page? > [Jane] The ONFI spec defines that the parameter page and its two redundant > copies are mandatory. > The additional redundant pages are optional. Currently, the FSL NAND driver > only reads the first > parameter page. This patch is to fix the driver to meet the mandatory > requirement in the spec. > We got a batch of particularly bad NAND chips recently and we needed these > changes to make them > work reliably over temperature. The patch was verified using these bad chips. I think Boris' remark was much more general than just this use case. The whole logic of tailoring ->cmdfunc() in each driver by guessing the data length, while there is absolutely no indication of it in this hook is broken. The core is moving to a new interface called ->exec_op(), and we would welcome a migration of this driver to this hook, that would be much much more easy to maintain for everyone. Thanks, Miquèl > > Best regards, > Jane > > Updated patch: > From 701de4146aa6355c951e97a77476e12d2da56d42 Mon Sep 17 00:00:00 2001 > From: Jane Wan <[email protected]> > Date: Mon, 30 Apr 2018 13:30:46 -0700 > Subject: [PATCH 1/2] mtd: rawnand: fsl_ifc: fix FSL NAND driver to read all > ONFI parameter pages > > Per ONFI specification (Rev. 4.0), if the CRC of the first parameter page > read is not valid, the host should read redundant parameter page copies. > Fix FSL NAND driver to read the two redundant copies which are mandatory > in the specification. > > Signed-off-by: Jane Wan <[email protected]> > --- > drivers/mtd/nand/raw/fsl_ifc_nand.c | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/drivers/mtd/nand/raw/fsl_ifc_nand.c > b/drivers/mtd/nand/raw/fsl_ifc_nand.c > index 61aae02..98aac1f 100644 > --- a/drivers/mtd/nand/raw/fsl_ifc_nand.c > +++ b/drivers/mtd/nand/raw/fsl_ifc_nand.c > @@ -342,9 +342,16 @@ static void fsl_ifc_cmdfunc(struct mtd_info *mtd, > unsigned int command, > > case NAND_CMD_READID: > case NAND_CMD_PARAM: { > + /* > + * For READID, read 8 bytes that are currently used. > + * For PARAM, read all 3 copies of 256-bytes pages. > + */ > + int len = 8; > int timing = IFC_FIR_OP_RB; > - if (command == NAND_CMD_PARAM) > + if (command == NAND_CMD_PARAM) { > timing = IFC_FIR_OP_RBCD; > + len = 256 * 3; > + } > > ifc_out32((IFC_FIR_OP_CW0 << IFC_NAND_FIR0_OP0_SHIFT) | > (IFC_FIR_OP_UA << IFC_NAND_FIR0_OP1_SHIFT) | > @@ -354,12 +361,8 @@ static void fsl_ifc_cmdfunc(struct mtd_info *mtd, > unsigned int command, > &ifc->ifc_nand.nand_fcr0); > ifc_out32(column, &ifc->ifc_nand.row3); > > - /* > - * although currently it's 8 bytes for READID, we always read > - * the maximum 256 bytes(for PARAM) > - */ > - ifc_out32(256, &ifc->ifc_nand.nand_fbcr); > - ifc_nand_ctrl->read_bytes = 256; > + ifc_out32(len, &ifc->ifc_nand.nand_fbcr); > + ifc_nand_ctrl->read_bytes = len; > > set_addr(mtd, 0, 0, 0); > fsl_ifc_run_command(mtd); -- Miquel Raynal, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com
