| Message ID | 1382619026-4182-5-git-send-email-pekon@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Oct 24, 2013 at 06:20:20PM +0530, Pekon Gupta wrote: > This patch: > - calls nand_scan_ident() using bus-width as passed by DT > - removes double calls to nand_scan_ident(), incase first call fails > then omap_nand_probe just returns error. > > Signed-off-by: Pekon Gupta <pekon@ti.com> > --- > drivers/mtd/nand/omap2.c | 21 +++++++++------------ > 1 file changed, 9 insertions(+), 12 deletions(-) > > diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c > index 5596368..f464321 100644 > --- a/drivers/mtd/nand/omap2.c > +++ b/drivers/mtd/nand/omap2.c > @@ -1856,7 +1856,6 @@ static int omap_nand_probe(struct platform_device *pdev) > mtd->name = dev_name(&pdev->dev); > mtd->owner = THIS_MODULE; > nand_chip = &info->nand; > - nand_chip->options = pdata->devsize; > nand_chip->options |= NAND_SKIP_BBTSCAN; > #ifdef CONFIG_MTD_NAND_OMAP_BCH > info->of_node = pdata->of_node; > @@ -1904,6 +1903,15 @@ static int omap_nand_probe(struct platform_device *pdev) > nand_chip->chip_delay = 50; > } > > + /* scan NAND device connected to chip controller */ > + nand_chip->options |= pdata->devsize & NAND_BUSWIDTH_16; Hm.. this only works if the device is listed in nand_flash_ids[] array, so that ONFI detection is not used. To make ONFI detection work I think you need to do as Brian suggested and use NAND_BUSWIDTH_AUTO. (Odd: why is there no current user of that auto-width option?) Anyway, I really think we should fix this now and independently of the evolution of this ECC DT binding discussion. That way you can keep sending a smaller ECC DT binding patchset and make reviewers focus on what's really important in each case. I have a few fixes (based on your work) and I'll send them now, after I complete the tests. We can continue our discussion there.
On Thu, Oct 24, 2013 at 06:27:15PM -0300, Ezequiel Garcia wrote: > On Thu, Oct 24, 2013 at 06:20:20PM +0530, Pekon Gupta wrote: > > This patch: > > - calls nand_scan_ident() using bus-width as passed by DT > > - removes double calls to nand_scan_ident(), incase first call fails > > then omap_nand_probe just returns error. > > > > Signed-off-by: Pekon Gupta <pekon@ti.com> > > --- > > drivers/mtd/nand/omap2.c | 21 +++++++++------------ > > 1 file changed, 9 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c > > index 5596368..f464321 100644 > > --- a/drivers/mtd/nand/omap2.c > > +++ b/drivers/mtd/nand/omap2.c > > @@ -1856,7 +1856,6 @@ static int omap_nand_probe(struct platform_device *pdev) > > mtd->name = dev_name(&pdev->dev); > > mtd->owner = THIS_MODULE; > > nand_chip = &info->nand; > > - nand_chip->options = pdata->devsize; > > nand_chip->options |= NAND_SKIP_BBTSCAN; > > #ifdef CONFIG_MTD_NAND_OMAP_BCH > > info->of_node = pdata->of_node; > > @@ -1904,6 +1903,15 @@ static int omap_nand_probe(struct platform_device *pdev) > > nand_chip->chip_delay = 50; > > } > > > > + /* scan NAND device connected to chip controller */ > > + nand_chip->options |= pdata->devsize & NAND_BUSWIDTH_16; > > Hm.. this only works if the device is listed in nand_flash_ids[] array, > so that ONFI detection is not used. But this is no more broken than it used to be, no? I mean, you would never properly detect an x16 ONFI flash with the old double-nand_scan_ident() method, right? > To make ONFI detection work I think you > need to do as Brian suggested and use NAND_BUSWIDTH_AUTO. I think that is the correct way forward. But Pekon seems to think that will require more invasive changes to the GPMC code. But I'm not sure why. > (Odd: why is there no current user of that auto-width option?) Hmm, I could have sworn somebody was using that... I know there was some pending work on using it for GPIO NAND, but Alexander Shiyan never followed up on the latest comments. It also seems like the original author (Matthieu Castet) was working on OMAP support about a year ago, but things stalled when there wasn't proper mainline support for much of it: http://thread.gmane.org/gmane.linux.ports.arm.omap/88550/focus=44770 Personally, I've only ever used x8 NAND, so I don't have much to go on here. > Anyway, I really think we should fix this now and independently > of the evolution of this ECC DT binding discussion. > That way you can keep sending a smaller ECC DT binding patchset and > make reviewers focus on what's really important in each case. AFAIK, the ECC DT bindings were all approved, and the code looked OK to my knowledge, except for this single patch. I had recommended either its total removal or its simplification (i.e., this current patch). I will be taking a last look and queueing this series up soon, I believe. > I have a few fixes (based on your work) and I'll send them now, after > I complete the tests. We can continue our discussion there. I'll take a look at those soon. So am I to understand you have hardware for testing Pekon's work now, Ezequiel? That will be great if we can have better Reviewed-by/Tested-by results. Brian -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Oct 24, 2013 at 03:43:00PM -0700, Brian Norris wrote: > On Thu, Oct 24, 2013 at 06:27:15PM -0300, Ezequiel Garcia wrote: > > On Thu, Oct 24, 2013 at 06:20:20PM +0530, Pekon Gupta wrote: > > > This patch: > > > - calls nand_scan_ident() using bus-width as passed by DT > > > - removes double calls to nand_scan_ident(), incase first call fails > > > then omap_nand_probe just returns error. > > > > > > Signed-off-by: Pekon Gupta <pekon@ti.com> > > > --- > > > drivers/mtd/nand/omap2.c | 21 +++++++++------------ > > > 1 file changed, 9 insertions(+), 12 deletions(-) > > > > > > diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c > > > index 5596368..f464321 100644 > > > --- a/drivers/mtd/nand/omap2.c > > > +++ b/drivers/mtd/nand/omap2.c > > > @@ -1856,7 +1856,6 @@ static int omap_nand_probe(struct platform_device *pdev) > > > mtd->name = dev_name(&pdev->dev); > > > mtd->owner = THIS_MODULE; > > > nand_chip = &info->nand; > > > - nand_chip->options = pdata->devsize; > > > nand_chip->options |= NAND_SKIP_BBTSCAN; > > > #ifdef CONFIG_MTD_NAND_OMAP_BCH > > > info->of_node = pdata->of_node; > > > @@ -1904,6 +1903,15 @@ static int omap_nand_probe(struct platform_device *pdev) > > > nand_chip->chip_delay = 50; > > > } > > > > > > + /* scan NAND device connected to chip controller */ > > > + nand_chip->options |= pdata->devsize & NAND_BUSWIDTH_16; > > > > Hm.. this only works if the device is listed in nand_flash_ids[] array, > > so that ONFI detection is not used. > > But this is no more broken than it used to be, no? I mean, you would > never properly detect an x16 ONFI flash with the old > double-nand_scan_ident() method, right? > That's right. But the issue is not really fixed either. > > To make ONFI detection work I think you > > need to do as Brian suggested and use NAND_BUSWIDTH_AUTO. > > I think that is the correct way forward. But Pekon seems to think that > will require more invasive changes to the GPMC code. But I'm not sure > why. > Hm... not sure. AFAIK, the GPMC should be *already* configured prior to the NAND driver being probed. > > (Odd: why is there no current user of that auto-width option?) > > Hmm, I could have sworn somebody was using that... I know there was some > pending work on using it for GPIO NAND, but Alexander Shiyan never > followed up on the latest comments. It also seems like the original > author (Matthieu Castet) was working on OMAP support about a year ago, > but things stalled when there wasn't proper mainline support for much of > it: > > http://thread.gmane.org/gmane.linux.ports.arm.omap/88550/focus=44770 > > Personally, I've only ever used x8 NAND, so I don't have much to go on > here. > > > Anyway, I really think we should fix this now and independently > > of the evolution of this ECC DT binding discussion. > > That way you can keep sending a smaller ECC DT binding patchset and > > make reviewers focus on what's really important in each case. > > AFAIK, the ECC DT bindings were all approved, and the code looked OK to > my knowledge, except for this single patch. I had recommended either its > total removal or its simplification (i.e., this current patch). > FWIW, I'm in favor of *completely* dropping whatever doesn't belong to the ECC DT binding. > I will be taking a last look and queueing this series up soon, I > believe. > > > I have a few fixes (based on your work) and I'll send them now, after > > I complete the tests. We can continue our discussion there. > > I'll take a look at those soon. > Ok, cool. > So am I to understand you have hardware for testing Pekon's work now, > Ezequiel? That will be great if we can have better Reviewed-by/Tested-by > results. > Yup, I gave it quick test actually, but nothing deep. Let me test some more maybe later today/tomorrow. I just wanted to sort this out first.
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 5596368..f464321 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1856,7 +1856,6 @@ static int omap_nand_probe(struct platform_device *pdev) mtd->name = dev_name(&pdev->dev); mtd->owner = THIS_MODULE; nand_chip = &info->nand; - nand_chip->options = pdata->devsize; nand_chip->options |= NAND_SKIP_BBTSCAN; #ifdef CONFIG_MTD_NAND_OMAP_BCH info->of_node = pdata->of_node; @@ -1904,6 +1903,15 @@ static int omap_nand_probe(struct platform_device *pdev) nand_chip->chip_delay = 50; } + /* scan NAND device connected to chip controller */ + nand_chip->options |= pdata->devsize & NAND_BUSWIDTH_16; + if (nand_scan_ident(mtd, 1, NULL)) { + pr_err("nand device scan failed, may be bus-width mismatch\n"); + err = -ENXIO; + goto out_release_mem_region; + } + + /* re-populate low-level callbacks based on xfer modes */ switch (pdata->xfer_type) { case NAND_OMAP_PREFETCH_POLLED: nand_chip->read_buf = omap_read_buf_pref; @@ -2011,17 +2019,6 @@ static int omap_nand_probe(struct platform_device *pdev) } } - /* DIP switches on some boards change between 8 and 16 bit - * bus widths for flash. Try the other width if the first try fails. - */ - if (nand_scan_ident(mtd, 1, NULL)) { - nand_chip->options ^= NAND_BUSWIDTH_16; - if (nand_scan_ident(mtd, 1, NULL)) { - err = -ENXIO; - goto out_release_mem_region; - } - } - /* rom code layout */ if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) {
This patch: - calls nand_scan_ident() using bus-width as passed by DT - removes double calls to nand_scan_ident(), incase first call fails then omap_nand_probe just returns error. Signed-off-by: Pekon Gupta <pekon@ti.com> --- drivers/mtd/nand/omap2.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-)