| Message ID | 1521564229-8018-1-git-send-email-jagdish.gediya@nxp.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] mtd: rawnand: fsl_ifc: Fix nand waitfunc return value | expand |
On Tue, 20 Mar 2018 22:13:38 +0530 Jagdish Gediya <jagdish.gediya@nxp.com> wrote: > As per the IFC hardware manual, Most significant 2 bytes in > nand_fsr register are the outcome of NAND READ STATUS command. > > So status value need to be shifted and aligned as per the nand > framework requirement. > > Fixes: 82771882d960 ("NAND Machine support for Integrated Flash Controller") > Cc: stable@vger.kernel.org # v3.18+ > Signed-off-by: Jagdish Gediya <jagdish.gediya@nxp.com> > Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com> > --- > Changes for v2: Incorporated comments from Boris Brezillon > - Added fixes tag > > drivers/mtd/nand/fsl_ifc_nand.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c > index 9390cbd..0aa03ba 100644 > --- a/drivers/mtd/nand/fsl_ifc_nand.c > +++ b/drivers/mtd/nand/fsl_ifc_nand.c > @@ -643,12 +643,13 @@ static int fsl_ifc_wait(struct mtd_info *mtd, struct nand_chip *chip) > fsl_ifc_run_command(mtd); > > nand_fsr = ifc_in32(&ifc->ifc_nand.nand_fsr); > - > + nand_fsr >>= 16; > + nand_fsr = (nand_fsr >> 8) | (nand_fsr << 8); Why are you swapping the upper and lower bytes? If the NAND status is stored in the upper byte of the fsr reg (bits 24 to 31), then shift the value by 24 directly. Note that (nand_fsr << 8) is useless here since you're masking nand_fsr with 0xff before returning it. > /* > * The chip always seems to report that it is > * write-protected, even when it is not. > */ > - return nand_fsr | NAND_STATUS_WP; > + return (nand_fsr & 0xff) | NAND_STATUS_WP; > } > > /*
Hi Boris, > -----Original Message----- > From: Boris Brezillon [mailto:boris.brezillon@bootlin.com] > Sent: Tuesday, March 20, 2018 1:51 PM > To: Jagdish Gediya <jagdish.gediya@nxp.com> > Cc: linux-mtd@lists.infradead.org; boris.brezillon@free-electrons.com; > computersforpeace@gmail.com; oss@buserror.net; Leo Li > <leoyang.li@nxp.com>; stable@vger.kernel.org > Subject: Re: [PATCH][v2] mtd: rawnand: fsl_ifc: Fix nand waitfunc return value > > On Tue, 20 Mar 2018 22:13:38 +0530 > Jagdish Gediya <jagdish.gediya@nxp.com> wrote: > > > As per the IFC hardware manual, Most significant 2 bytes in nand_fsr > > register are the outcome of NAND READ STATUS command. > > > > So status value need to be shifted and aligned as per the nand > > framework requirement. > > > > Fixes: 82771882d960 ("NAND Machine support for Integrated Flash > > Controller") > > Cc: stable@vger.kernel.org # v3.18+ > > Signed-off-by: Jagdish Gediya <jagdish.gediya@nxp.com> > > Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com> > > --- > > Changes for v2: Incorporated comments from Boris Brezillon > > - Added fixes tag > > > > drivers/mtd/nand/fsl_ifc_nand.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/mtd/nand/fsl_ifc_nand.c > > b/drivers/mtd/nand/fsl_ifc_nand.c index 9390cbd..0aa03ba 100644 > > --- a/drivers/mtd/nand/fsl_ifc_nand.c > > +++ b/drivers/mtd/nand/fsl_ifc_nand.c > > @@ -643,12 +643,13 @@ static int fsl_ifc_wait(struct mtd_info *mtd, struct > nand_chip *chip) > > fsl_ifc_run_command(mtd); > > > > nand_fsr = ifc_in32(&ifc->ifc_nand.nand_fsr); > > - > > + nand_fsr >>= 16; > > + nand_fsr = (nand_fsr >> 8) | (nand_fsr << 8); > > Why are you swapping the upper and lower bytes? If the NAND status is stored > in the upper byte of the fsr reg (bits 24 to 31), then shift the value by 24 > directly. Note that (nand_fsr << 8) is useless here since you're masking > nand_fsr with 0xff before returning it. > nand_fsr register is, 31 0 --------------------------------------------- | RS0 | RS1 | reserved | reserved | --------------------------------------------- I intended to make it, 31 0 ----------------------------- | 00 | 00 | RS1 | RS0 | ----------------------------- RS0 gets the nand read status. I am not dropping RS1 value for possible future use. > > /* > > * The chip always seems to report that it is > > * write-protected, even when it is not. > > */ > > - return nand_fsr | NAND_STATUS_WP; > > + return (nand_fsr & 0xff) | NAND_STATUS_WP; It should be 0xffff instead of 0xff. > > } > > > > /* > > > Thanks, Jagdish
On Tue, 20 Mar 2018 10:16:04 +0000 Jagdish Gediya <jagdish.gediya@nxp.com> wrote: > Hi Boris, > > > -----Original Message----- > > From: Boris Brezillon [mailto:boris.brezillon@bootlin.com] > > Sent: Tuesday, March 20, 2018 1:51 PM > > To: Jagdish Gediya <jagdish.gediya@nxp.com> > > Cc: linux-mtd@lists.infradead.org; boris.brezillon@free-electrons.com; > > computersforpeace@gmail.com; oss@buserror.net; Leo Li > > <leoyang.li@nxp.com>; stable@vger.kernel.org > > Subject: Re: [PATCH][v2] mtd: rawnand: fsl_ifc: Fix nand waitfunc return value > > > > On Tue, 20 Mar 2018 22:13:38 +0530 > > Jagdish Gediya <jagdish.gediya@nxp.com> wrote: > > > > > As per the IFC hardware manual, Most significant 2 bytes in nand_fsr > > > register are the outcome of NAND READ STATUS command. > > > > > > So status value need to be shifted and aligned as per the nand > > > framework requirement. > > > > > > Fixes: 82771882d960 ("NAND Machine support for Integrated Flash > > > Controller") > > > Cc: stable@vger.kernel.org # v3.18+ > > > Signed-off-by: Jagdish Gediya <jagdish.gediya@nxp.com> > > > Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com> > > > --- > > > Changes for v2: Incorporated comments from Boris Brezillon > > > - Added fixes tag > > > > > > drivers/mtd/nand/fsl_ifc_nand.c | 5 +++-- > > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/mtd/nand/fsl_ifc_nand.c > > > b/drivers/mtd/nand/fsl_ifc_nand.c index 9390cbd..0aa03ba 100644 > > > --- a/drivers/mtd/nand/fsl_ifc_nand.c > > > +++ b/drivers/mtd/nand/fsl_ifc_nand.c > > > @@ -643,12 +643,13 @@ static int fsl_ifc_wait(struct mtd_info *mtd, struct > > nand_chip *chip) > > > fsl_ifc_run_command(mtd); > > > > > > nand_fsr = ifc_in32(&ifc->ifc_nand.nand_fsr); > > > - > > > + nand_fsr >>= 16; > > > + nand_fsr = (nand_fsr >> 8) | (nand_fsr << 8); > > > > Why are you swapping the upper and lower bytes? If the NAND status is stored > > in the upper byte of the fsr reg (bits 24 to 31), then shift the value by 24 > > directly. Note that (nand_fsr << 8) is useless here since you're masking > > nand_fsr with 0xff before returning it. > > > nand_fsr register is, > 31 0 > --------------------------------------------- > | RS0 | RS1 | reserved | reserved | > --------------------------------------------- > I intended to make it, > 31 0 > ----------------------------- > | 00 | 00 | RS1 | RS0 | > ----------------------------- > RS0 gets the nand read status. I am not dropping RS1 value for possible future use. Then store the nand status in a different var and keep nand_fsr untouched: status = nand_fsr >> 24; Note that I don't see the point of keeping RS1 until you really need it. > > > /* > > > * The chip always seems to report that it is > > > * write-protected, even when it is not. > > > */ > > > - return nand_fsr | NAND_STATUS_WP; > > > + return (nand_fsr & 0xff) | NAND_STATUS_WP; > It should be 0xffff instead of 0xff. No it should not. The ->waitfunc() semantic is enforced by the framework and it expects a NAND status *byte*.
diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c index 9390cbd..0aa03ba 100644 --- a/drivers/mtd/nand/fsl_ifc_nand.c +++ b/drivers/mtd/nand/fsl_ifc_nand.c @@ -643,12 +643,13 @@ static int fsl_ifc_wait(struct mtd_info *mtd, struct nand_chip *chip) fsl_ifc_run_command(mtd); nand_fsr = ifc_in32(&ifc->ifc_nand.nand_fsr); - + nand_fsr >>= 16; + nand_fsr = (nand_fsr >> 8) | (nand_fsr << 8); /* * The chip always seems to report that it is * write-protected, even when it is not. */ - return nand_fsr | NAND_STATUS_WP; + return (nand_fsr & 0xff) | NAND_STATUS_WP; } /*
As per the IFC hardware manual, Most significant 2 bytes in nand_fsr register are the outcome of NAND READ STATUS command. So status value need to be shifted and aligned as per the nand framework requirement. Fixes: 82771882d960 ("NAND Machine support for Integrated Flash Controller") Cc: stable@vger.kernel.org # v3.18+ Signed-off-by: Jagdish Gediya <jagdish.gediya@nxp.com> Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com> --- Changes for v2: Incorporated comments from Boris Brezillon - Added fixes tag drivers/mtd/nand/fsl_ifc_nand.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)