[PATCH 1/2] mtd: m25p80: Reworkprobing/JEDEC code
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From: Anton Vorontsov on 21 Jun 2010 03:20 On Mon, Jun 21, 2010 at 11:27:31AM +0800, Barry Song wrote: [...] > > How about we add a non_jedec flag in platform_data, if the flag is 1, we > > let the detection pass even though the ID is 0? Otherwise, we need a > > valid ID? > Here i mean: This will break at least OF-enabled platforms (e.g. PowerPC), they assume that the driver will success for non-JEDEC flashes. OF platforms don't pass platform data, and even if they did, device tree doesn't specify if the flash is JEDEC or non-JEDEC. Which is why I think that, by default, the driver should successfully register the flash even if JEDEC probe fails. So, instead of checking for "!non_jedec", I would recommend "force_jedec" check. > Index: drivers/mtd/devices/m25p80.c > =================================================================== > --- drivers/mtd/devices/m25p80.c (revision 8927) > +++ drivers/mtd/devices/m25p80.c (revision 8929) > @@ -795,8 +795,13 @@ > > jid = jedec_probe(spi); > if (!jid) { > - dev_info(&spi->dev, "non-JEDEC variant of %s\n", > - id->name); > + if (!data->non_jedec) { > + dev_err(&spi->dev, "fail to detect%s\n", > + id->name); > + return -ENODEV; > + } else > + dev_info(&spi->dev, "non-JEDEC variant of %s\n", > + id->name); > } else if (jid != id) { -- Anton Vorontsov email: cbouatmailru(a)gmail.com irc://irc.freenode.net/bd2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Anton Vorontsov on 21 Jun 2010 03:40 On Mon, Jun 21, 2010 at 03:22:48PM +0800, Barry Song wrote: > On Mon, Jun 21, 2010 at 3:15 PM, Anton Vorontsov <cbouatmailru(a)gmail.com> wrote: > > On Mon, Jun 21, 2010 at 11:27:31AM +0800, Barry Song wrote: > > [...] > >> > How about we add a non_jedec flag in platform_data, if the flag is 1, we > >> > let the detection pass even though the ID is 0? Otherwise, we need a > >> > valid ID? > >> Here i mean: > > > > This will break at least OF-enabled platforms (e.g. PowerPC), > > they assume that the driver will success for non-JEDEC flashes. > > OF platforms don't pass platform data, and even if they did, > > device tree doesn't specify if the flash is JEDEC or non-JEDEC. > > > > Which is why I think that, by default, the driver should > > successfully register the flash even if JEDEC probe fails. So, > > instead of checking for "!non_jedec", I would recommend > > "force_jedec" check. > > Mike Frysinger suggested to use non_jedec since most devices are > standard jedec devices. Well, on OF platforms most devices that I'm aware of are non-JEDEC. > Only if non_jedec=1, we let the detection pass > if ID is 0. Then please #ifdef it with CONFIG_OF. Thanks, > >> Index: drivers/mtd/devices/m25p80.c > >> =================================================================== > >> --- drivers/mtd/devices/m25p80.c (revision 8927) > >> +++ drivers/mtd/devices/m25p80.c (revision 8929) > >> @@ -795,8 +795,13 @@ > >> > >> jid = jedec_probe(spi); > >> if (!jid) { > >> - dev_info(&spi->dev, "non-JEDEC variant of %s\n", > >> - id->name); > >> + if (!data->non_jedec) { > >> + dev_err(&spi->dev, "fail to detect%s\n", > >> + id->name); > >> + return -ENODEV; > >> + } else > >> + dev_info(&spi->dev, "non-JEDEC variant of %s\n", > >> + id->name); > >> } else if (jid != id) { > > > > -- > > Anton Vorontsov > > email: cbouatmailru(a)gmail.com > > irc://irc.freenode.net/bd2 > > -- Anton Vorontsov email: cbouatmailru(a)gmail.com irc://irc.freenode.net/bd2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Anton Vorontsov on 21 Jun 2010 07:30 On Mon, Jun 21, 2010 at 06:31:44PM +0800, Barry Song wrote: > On Mon, Jun 21, 2010 at 3:39 PM, Anton Vorontsov <cbouatmailru(a)gmail.com> wrote: > > On Mon, Jun 21, 2010 at 03:22:48PM +0800, Barry Song wrote: > >> On Mon, Jun 21, 2010 at 3:15 PM, Anton Vorontsov <cbouatmailru(a)gmail.com> wrote: > >> > On Mon, Jun 21, 2010 at 11:27:31AM +0800, Barry Song wrote: > >> > [...] > >> >> > How about we add a non_jedec flag in platform_data, if the flag is 1, we > >> >> > let the detection pass even though the ID is 0? Otherwise, we need a > >> >> > valid ID? > >> >> Here i mean: > >> > > >> > This will break at least OF-enabled platforms (e.g. PowerPC), > >> > they assume that the driver will success for non-JEDEC flashes. > >> > OF platforms don't pass platform data, and even if they did, > >> > device tree doesn't specify if the flash is JEDEC or non-JEDEC. > >> > > >> > Which is why I think that, by default, the driver should > >> > successfully register the flash even if JEDEC probe fails. So, > >> > instead of checking for "!non_jedec", I would recommend > >> > "force_jedec" check. > >> > >> Mike Frysinger suggested to use non_jedec since most devices are > >> standard jedec devices. > > > > Well, on OF platforms most devices that I'm aware of are non-JEDEC. > > > >> Only if non_jedec=1, we let the detection pass > >> if ID is 0. > > > > Then please #ifdef it with CONFIG_OF. > I think the patch has nothing to do with platform. Here SPI Flash is a > peripherals, doesn't depend on any platform. Adding a CONFIG_OF > doesn't make sense very much. With OF we don't place non-existent devices into the device tree (or we mark them with status = "not-ok/disabled/absent" property). > If you think most devices are non-JEDEC, we can change non_JEDEC to > force_JEDEC as you said. > But anyway, is that real that most devices are non_JEDEC? Why would this matter? We have to support both. > If not, I think we should change OF platform codes to > fit with this patch. You can't easily change OF. It's like "let's change ACPI tables or BIOS in these PCs". Doable, but involves things like reflashing. And we usually have to support old BIOSes as well. OTOH, I see (git grep m25p arch/powerpc/boot/dts/) that in mainline kernel only MPC8569 board has a correct m25p node, and it is STMicro variant (it is JEDEC capable). As we don't really have to support out of tree code, I'd just go with this patch, assuming that we have to change device tree for boards with non-JEDEC flashes. It's effectively the same thing as platform data flag, except that it works automatically for OF platforms. Signed-off-by: Anton Vorontsov <avorontsov(a)mvista.com> --- diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c index 81e49a9..a610ca9 100644 --- a/drivers/mtd/devices/m25p80.c +++ b/drivers/mtd/devices/m25p80.c @@ -680,6 +680,16 @@ static const struct spi_device_id m25p_ids[] = { { "m25p64", INFO(0x202017, 0, 64 * 1024, 128, 0) }, { "m25p128", INFO(0x202018, 0, 256 * 1024, 64, 0) }, + { "m25p05-nonjedec", INFO(0, 0, 32 * 1024, 2, 0) }, + { "m25p10-nonjedec", INFO(0, 0, 32 * 1024, 4, 0) }, + { "m25p20-nonjedec", INFO(0, 0, 64 * 1024, 4, 0) }, + { "m25p40-nonjedec", INFO(0, 0, 64 * 1024, 8, 0) }, + { "m25p80-nonjedec", INFO(0, 0, 64 * 1024, 16, 0) }, + { "m25p16-nonjedec", INFO(0, 0, 64 * 1024, 32, 0) }, + { "m25p32-nonjedec", INFO(0, 0, 64 * 1024, 64, 0) }, + { "m25p64-nonjedec", INFO(0, 0, 64 * 1024, 128, 0) }, + { "m25p128-nonjedec", INFO(0, 0, 256 * 1024, 64, 0) }, + { "m45pe10", INFO(0x204011, 0, 64 * 1024, 2, 0) }, { "m45pe80", INFO(0x204014, 0, 64 * 1024, 16, 0) }, { "m45pe16", INFO(0x204015, 0, 64 * 1024, 32, 0) }, @@ -795,8 +805,7 @@ static int __devinit m25p_probe(struct spi_device *spi) jid = jedec_probe(spi); if (!jid) { - dev_info(&spi->dev, "non-JEDEC variant of %s\n", - id->name); + return -ENODEV; } else if (jid != id) { /* * JEDEC knows better, so overwrite platform ID. We -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Anton Vorontsov on 21 Jun 2010 12:50 On Mon, Jun 21, 2010 at 12:34:05PM -0400, Mike Frysinger wrote: > On Mon, Jun 21, 2010 at 07:20, Anton Vorontsov wrote: > > You can't easily change OF. It's like "let's change ACPI tables > > or BIOS in these PCs". Doable, but involves things like reflashing. > > And we usually have to support old BIOSes as well. > > > > OTOH, I see (git grep m25p arch/powerpc/boot/dts/) that in > > mainline kernel only MPC8569 board has a correct m25p > > node, and it is STMicro variant (it is JEDEC capable). > > > > As we don't really have to support out of tree code, I'd > > just go with this patch, assuming that we have to change > > device tree for boards with non-JEDEC flashes. It's > > effectively the same thing as platform data flag, except > > that it works automatically for OF platforms. > > > > diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c > > index 81e49a9..a610ca9 100644 > > --- a/drivers/mtd/devices/m25p80.c > > +++ b/drivers/mtd/devices/m25p80.c > > @@ -680,6 +680,16 @@ static const struct spi_device_id m25p_ids[] = { > > { "m25p64", INFO(0x202017, 0, 64 * 1024, 128, 0) }, > > { "m25p128", INFO(0x202018, 0, 256 * 1024, 64, 0) }, > > > > + { "m25p05-nonjedec", INFO(0, 0, 32 * 1024, 2, 0) }, > > + { "m25p10-nonjedec", INFO(0, 0, 32 * 1024, 4, 0) }, > > + { "m25p20-nonjedec", INFO(0, 0, 64 * 1024, 4, 0) }, > > + { "m25p40-nonjedec", INFO(0, 0, 64 * 1024, 8, 0) }, > > + { "m25p80-nonjedec", INFO(0, 0, 64 * 1024, 16, 0) }, > > + { "m25p16-nonjedec", INFO(0, 0, 64 * 1024, 32, 0) }, > > + { "m25p32-nonjedec", INFO(0, 0, 64 * 1024, 64, 0) }, > > + { "m25p64-nonjedec", INFO(0, 0, 64 * 1024, 128, 0) }, > > + { "m25p128-nonjedec", INFO(0, 0, 256 * 1024, 64, 0) }, > > + > > are you picking the m25p because its flash geometry matches whatever > you're using, or because you have some weird variant of the m25p that > has JEDEC commands removed ? The latter. It's Numonyx M25Pxx flashes, see http://www.numonyx.com/Documents/Datasheets/M25P80.pdf The RDID instruction is available only for parts made with 110 nm Technology identified with Process letter '4'. -- Anton Vorontsov email: cbouatmailru(a)gmail.com irc://irc.freenode.net/bd2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Anton Vorontsov on 22 Jun 2010 13:00
On Tue, Jun 22, 2010 at 02:37:52PM +0800, Barry Song wrote: [...] > > jid = jedec_probe(spi); > > if (!jid) { > > - dev_info(&spi->dev, "non-JEDEC variant of %s\n", > > - id->name); > > + return -ENODEV; > The patch looks good to me. Only problem is NULL is also returned by > spi_write_then_read() fail: [...] > Here much better for -EIO (return tmp)? Agreed. Though, this is not a regression, and I guess desires its own patch. Here are two patches, one for 2.6.35 (minimal changes to fix the JEDEC problem), another for 2.6.36. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |