| Message ID | 1452762920-2588-1-git-send-email-kishon@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Thu, Jan 14, 2016 at 02:45:20PM +0530, Kishon Vijay Abraham I wrote: > Since v4.3+, CONFIG_REGULATOR_PBIAS should be enabled (for platforms that > have PBIAS regulator) in order for MMC1 to work. > > Add a more verbose print to help enable CONFIG_REGULATOR_PBIAS for users > using a olddefconfig or a custom .config. > > Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> > --- > drivers/mmc/host/omap_hsmmc.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > index 7fb0753..7086bd6 100644 > --- a/drivers/mmc/host/omap_hsmmc.c > +++ b/drivers/mmc/host/omap_hsmmc.c > @@ -503,8 +503,11 @@ static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host) > host->pbias = devm_regulator_get_optional(host->dev, "pbias"); > if (IS_ERR(host->pbias)) { > ret = PTR_ERR(host->pbias); > - if ((ret != -ENODEV) && host->dev->of_node) > + if ((ret != -ENODEV) && host->dev->of_node) { > + dev_err(host->dev, > + "SD card detect fail? enable CONFIG_REGULATOR_PBIAS\n"); > return ret; > + } > dev_dbg(host->dev, "unable to get pbias regulator %ld\n", > PTR_ERR(host->pbias)); > host->pbias = NULL; Is there a good reason against adding "depends on REGULATOR_PBIAS" to MMC_OMAP_HS? I guess it's required for most systems and the regulator driver is just 250 loc. I am aware, that this will disable the hsmmc driver for 'make oldconfig', but I guess that will be noticed in a similar way your warning is noticed. The advantage of having the depends line is, that people configuring their kernel have a chance to notice the regulator requirement during configuration. Anyways, this message improves the situation, so: Acked-By: Sebastian Reichel <sre@kernel.org> -- Sebastian
Hi, On Thursday 14 January 2016 05:37 PM, Sebastian Reichel wrote: > Hi, > > On Thu, Jan 14, 2016 at 02:45:20PM +0530, Kishon Vijay Abraham I wrote: >> Since v4.3+, CONFIG_REGULATOR_PBIAS should be enabled (for platforms that >> have PBIAS regulator) in order for MMC1 to work. >> >> Add a more verbose print to help enable CONFIG_REGULATOR_PBIAS for users >> using a olddefconfig or a custom .config. >> >> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> >> --- >> drivers/mmc/host/omap_hsmmc.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c >> index 7fb0753..7086bd6 100644 >> --- a/drivers/mmc/host/omap_hsmmc.c >> +++ b/drivers/mmc/host/omap_hsmmc.c >> @@ -503,8 +503,11 @@ static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host) >> host->pbias = devm_regulator_get_optional(host->dev, "pbias"); >> if (IS_ERR(host->pbias)) { >> ret = PTR_ERR(host->pbias); >> - if ((ret != -ENODEV) && host->dev->of_node) >> + if ((ret != -ENODEV) && host->dev->of_node) { >> + dev_err(host->dev, >> + "SD card detect fail? enable CONFIG_REGULATOR_PBIAS\n"); >> return ret; >> + } >> dev_dbg(host->dev, "unable to get pbias regulator %ld\n", >> PTR_ERR(host->pbias)); >> host->pbias = NULL; > > > Is there a good reason against adding "depends on REGULATOR_PBIAS" > to MMC_OMAP_HS? I guess it's required for most systems and the regulator > driver is just 250 loc. I am aware, that this will disable the > hsmmc driver for 'make oldconfig', but I guess that will be noticed > in a similar way your warning is noticed. hmm.. only MMC1 requires PBIAS so I'm not sure if it's okay to add depends on REGULATOR_PBIAS for the HSMMC driver as such. And as you said it'll also disable the hsmmc driver if oldconfig is used. But do we get a warning? Thanks Kishon -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
* Kishon Vijay Abraham I <kishon@ti.com> [160114 04:39]: > On Thursday 14 January 2016 05:37 PM, Sebastian Reichel wrote: > > > > Is there a good reason against adding "depends on REGULATOR_PBIAS" > > to MMC_OMAP_HS? I guess it's required for most systems and the regulator > > driver is just 250 loc. I am aware, that this will disable the > > hsmmc driver for 'make oldconfig', but I guess that will be noticed > > in a similar way your warning is noticed. > > hmm.. only MMC1 requires PBIAS so I'm not sure if it's okay to add depends on > REGULATOR_PBIAS for the HSMMC driver as such. And as you said it'll also > disable the hsmmc driver if oldconfig is used. But do we get a warning? Adding depends there is a bit wrong, many designs are not using MMC1 but use eMMC on the other controllers instead. I think the runtime warning is best we can do here to keep things modular. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jan 14, 2016 at 01:07:06PM +0100, Sebastian Reichel wrote: > Hi, > > On Thu, Jan 14, 2016 at 02:45:20PM +0530, Kishon Vijay Abraham I wrote: > > Since v4.3+, CONFIG_REGULATOR_PBIAS should be enabled (for platforms that > > have PBIAS regulator) in order for MMC1 to work. > > > > Add a more verbose print to help enable CONFIG_REGULATOR_PBIAS for users > > using a olddefconfig or a custom .config. > > > > Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> > > --- > > drivers/mmc/host/omap_hsmmc.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > > index 7fb0753..7086bd6 100644 > > --- a/drivers/mmc/host/omap_hsmmc.c > > +++ b/drivers/mmc/host/omap_hsmmc.c > > @@ -503,8 +503,11 @@ static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host) > > host->pbias = devm_regulator_get_optional(host->dev, "pbias"); > > if (IS_ERR(host->pbias)) { > > ret = PTR_ERR(host->pbias); > > - if ((ret != -ENODEV) && host->dev->of_node) > > + if ((ret != -ENODEV) && host->dev->of_node) { > > + dev_err(host->dev, > > + "SD card detect fail? enable CONFIG_REGULATOR_PBIAS\n"); > > return ret; > > + } > > dev_dbg(host->dev, "unable to get pbias regulator %ld\n", > > PTR_ERR(host->pbias)); > > host->pbias = NULL; > > > Is there a good reason against adding "depends on REGULATOR_PBIAS" > to MMC_OMAP_HS? There are very good reasons not to do this: that will result in configurations where MMC_OMAP_HS was set but without REGULATOR_PBIAS ending up with MMC_OMAP_HS being disabled. That doesn't help the root problem, which is "why has the kernel boot regressed for my previous working configuration?" The solution proposed here adds a message to the boot which points out fair and square what needs to be done to rectify the boot failure. Adding a dependency just brings up the question "where has my MMC driver gone?"
Hi, On Thu, Jan 14, 2016 at 05:25:49PM +0000, Russell King - ARM Linux wrote: > On Thu, Jan 14, 2016 at 01:07:06PM +0100, Sebastian Reichel wrote: > > On Thu, Jan 14, 2016 at 02:45:20PM +0530, Kishon Vijay Abraham I wrote: > > > Since v4.3+, CONFIG_REGULATOR_PBIAS should be enabled (for platforms that > > > have PBIAS regulator) in order for MMC1 to work. > > > > > > Add a more verbose print to help enable CONFIG_REGULATOR_PBIAS for users > > > using a olddefconfig or a custom .config. > > > > > > Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> > > > --- > > > drivers/mmc/host/omap_hsmmc.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > > > index 7fb0753..7086bd6 100644 > > > --- a/drivers/mmc/host/omap_hsmmc.c > > > +++ b/drivers/mmc/host/omap_hsmmc.c > > > @@ -503,8 +503,11 @@ static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host) > > > host->pbias = devm_regulator_get_optional(host->dev, "pbias"); > > > if (IS_ERR(host->pbias)) { > > > ret = PTR_ERR(host->pbias); > > > - if ((ret != -ENODEV) && host->dev->of_node) > > > + if ((ret != -ENODEV) && host->dev->of_node) { > > > + dev_err(host->dev, > > > + "SD card detect fail? enable CONFIG_REGULATOR_PBIAS\n"); > > > return ret; > > > + } > > > dev_dbg(host->dev, "unable to get pbias regulator %ld\n", > > > PTR_ERR(host->pbias)); > > > host->pbias = NULL; > > > > > > Is there a good reason against adding "depends on REGULATOR_PBIAS" > > to MMC_OMAP_HS? > > There are very good reasons not to do this: that will result in > configurations where MMC_OMAP_HS was set but without REGULATOR_PBIAS > ending up with MMC_OMAP_HS being disabled. That doesn't help the > root problem, which is "why has the kernel boot regressed for my > previous working configuration?" > > The solution proposed here adds a message to the boot which points > out fair and square what needs to be done to rectify the boot > failure. Adding a dependency just brings up the question "where > has my MMC driver gone?" The best thing would be to have no regression. Just printing a message means I have to build another kernel. But more importantly the message may not be visible by the user - e.g. if the display has not yet been initialized. -- Sebastian
On Thu, Jan 14, 2016 at 11:40:25PM +0100, Sebastian Reichel wrote: > On Thu, Jan 14, 2016 at 05:25:49PM +0000, Russell King - ARM Linux wrote: > > There are very good reasons not to do this: that will result in > > configurations where MMC_OMAP_HS was set but without REGULATOR_PBIAS > > ending up with MMC_OMAP_HS being disabled. That doesn't help the > > root problem, which is "why has the kernel boot regressed for my > > previous working configuration?" > > > > The solution proposed here adds a message to the boot which points > > out fair and square what needs to be done to rectify the boot > > failure. Adding a dependency just brings up the question "where > > has my MMC driver gone?" > > The best thing would be to have no regression. Just printing a > message means I have to build another kernel. But more importantly > the message may not be visible by the user - e.g. if the display has > not yet been initialized. I agree in principle, but that's not possible here (see Tony's mails on why the PBIAS stuff needs to be optional.) I'd agree with changing the Kconfig if PBIAS were a hard and fast requirement, but it isn't.
* Russell King - ARM Linux <linux@arm.linux.org.uk> [160115 01:15]: > On Thu, Jan 14, 2016 at 11:40:25PM +0100, Sebastian Reichel wrote: > > On Thu, Jan 14, 2016 at 05:25:49PM +0000, Russell King - ARM Linux wrote: > > > There are very good reasons not to do this: that will result in > > > configurations where MMC_OMAP_HS was set but without REGULATOR_PBIAS > > > ending up with MMC_OMAP_HS being disabled. That doesn't help the > > > root problem, which is "why has the kernel boot regressed for my > > > previous working configuration?" > > > > > > The solution proposed here adds a message to the boot which points > > > out fair and square what needs to be done to rectify the boot > > > failure. Adding a dependency just brings up the question "where > > > has my MMC driver gone?" > > > > The best thing would be to have no regression. Just printing a > > message means I have to build another kernel. But more importantly > > the message may not be visible by the user - e.g. if the display has > > not yet been initialized. > > I agree in principle, but that's not possible here (see Tony's mails > on why the PBIAS stuff needs to be optional.) I'd agree with changing > the Kconfig if PBIAS were a hard and fast requirement, but it isn't. Yeah. Probably the best solution for cases like this is to boot with a small initrd. That way you can get usb console and networking going before mounting the real root and you will see kernel messages with only minimal things built in. You can build a small initramfs with CONFIG_INITRAMFS_SOURCE that is appended to the kernel so you can also boot the legacy user space too with that if needed. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 14 January 2016 at 10:15, Kishon Vijay Abraham I <kishon@ti.com> wrote: > Since v4.3+, CONFIG_REGULATOR_PBIAS should be enabled (for platforms that > have PBIAS regulator) in order for MMC1 to work. > > Add a more verbose print to help enable CONFIG_REGULATOR_PBIAS for users > using a olddefconfig or a custom .config. > > Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Thanks,applied for next! Kind regards Uffe > --- > drivers/mmc/host/omap_hsmmc.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c > index 7fb0753..7086bd6 100644 > --- a/drivers/mmc/host/omap_hsmmc.c > +++ b/drivers/mmc/host/omap_hsmmc.c > @@ -503,8 +503,11 @@ static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host) > host->pbias = devm_regulator_get_optional(host->dev, "pbias"); > if (IS_ERR(host->pbias)) { > ret = PTR_ERR(host->pbias); > - if ((ret != -ENODEV) && host->dev->of_node) > + if ((ret != -ENODEV) && host->dev->of_node) { > + dev_err(host->dev, > + "SD card detect fail? enable CONFIG_REGULATOR_PBIAS\n"); > return ret; > + } > dev_dbg(host->dev, "unable to get pbias regulator %ld\n", > PTR_ERR(host->pbias)); > host->pbias = NULL; > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 7fb0753..7086bd6 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -503,8 +503,11 @@ static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host) host->pbias = devm_regulator_get_optional(host->dev, "pbias"); if (IS_ERR(host->pbias)) { ret = PTR_ERR(host->pbias); - if ((ret != -ENODEV) && host->dev->of_node) + if ((ret != -ENODEV) && host->dev->of_node) { + dev_err(host->dev, + "SD card detect fail? enable CONFIG_REGULATOR_PBIAS\n"); return ret; + } dev_dbg(host->dev, "unable to get pbias regulator %ld\n", PTR_ERR(host->pbias)); host->pbias = NULL;
Since v4.3+, CONFIG_REGULATOR_PBIAS should be enabled (for platforms that have PBIAS regulator) in order for MMC1 to work. Add a more verbose print to help enable CONFIG_REGULATOR_PBIAS for users using a olddefconfig or a custom .config. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> --- drivers/mmc/host/omap_hsmmc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)