Messages in this thread | | | Date | Wed, 13 Dec 2017 10:53:45 +0100 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH V4 08/12] boot_constraint: Manage deferrable constraints |
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On Sun, Oct 29, 2017 at 07:18:56PM +0530, Viresh Kumar wrote: > It is possible that some of the resources aren't available at the time > constraints are getting set and the boot constraints core will return > -EPROBE_DEFER for them. In order to retry adding the constraints at a > later point of time (after the resource is added and before any of its > users come up), this patch proposes two things: > > - Each constraint is represented by a virtual platform device, so that > it is re-probed again until the time all the dependencies aren't met. > The platform device is removed along with the constraint, with help of > the free_resources() callback. > > - Enable early defer probing support by calling > driver_enable_deferred_probe(), so that the core retries probing > deferred devices every time any device is bound to a driver. This > makes sure that the constraint is set before any of the users of the > resources come up. > > This is tested on ARM64 Hikey board where probe was deferred for a > device. > > Tested-by: Rajendra Nayak <rnayak@codeaurora.org> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > --- > drivers/base/dd.c | 12 ++ > drivers/boot_constraints/Makefile | 2 +- > drivers/boot_constraints/deferrable_dev.c | 235 ++++++++++++++++++++++++++++++ > include/linux/boot_constraint.h | 14 ++ > 4 files changed, 262 insertions(+), 1 deletion(-) > create mode 100644 drivers/boot_constraints/deferrable_dev.c > > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 4eec27fe2b2b..19eff5d08b9a 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -228,6 +228,18 @@ void device_unblock_probing(void) > driver_deferred_probe_trigger(); > } > > +/** > + * driver_enable_deferred_probe() - Enable probing of deferred devices > + * > + * We don't want to get in the way when the bulk of drivers are getting probed > + * and so deferred probe is disabled in the beginning. Enable it now because we > + * need it. > + */ > +void driver_enable_deferred_probe(void) > +{ > + driver_deferred_probe_enable = true; > +} > + > /** > * deferred_probe_initcall() - Enable probing of deferred devices > * > diff --git a/drivers/boot_constraints/Makefile b/drivers/boot_constraints/Makefile > index b7ade1a7afb5..a765094623a3 100644 > --- a/drivers/boot_constraints/Makefile > +++ b/drivers/boot_constraints/Makefile > @@ -1,3 +1,3 @@ > # Makefile for device boot constraints > > -obj-y := clk.o core.o pm.o supply.o > +obj-y := clk.o deferrable_dev.o core.o pm.o supply.o > diff --git a/drivers/boot_constraints/deferrable_dev.c b/drivers/boot_constraints/deferrable_dev.c > new file mode 100644 > index 000000000000..04056f317aff > --- /dev/null > +++ b/drivers/boot_constraints/deferrable_dev.c > @@ -0,0 +1,235 @@ > +/* > + * Copyright (C) 2017 Linaro. > + * Viresh Kumar <viresh.kumar@linaro.org> > + * > + * This file is released under the GPLv2. > + */ > + > +#define pr_fmt(fmt) "Boot Constraints: " fmt
Hey, you use this one!
But you shouldn't :)
> +/* This only creates platform devices for now */ > +static void add_deferrable_of_single(struct device_node *np, > + struct dev_boot_constraint *constraints, > + int count) > +{ > + struct device *dev; > + int ret; > + > + if (!of_device_is_available(np)) > + return; > + > + ret = of_platform_bus_create(np, NULL, NULL, NULL, false); > + if (ret) > + return; > + > + if (of_device_is_compatible(np, "arm,primecell")) {
Why is "arm,primecell" in the core code here?
> + struct amba_device *adev = of_find_amba_device_by_node(np); > + > + if (!adev) { > + pr_err("Failed to find amba dev: %s\n", np->full_name);
Never use pr_* when you have a valid struct device to use. Don't you have one from the struct device_node * passed in here?
> + return; > + } > + dev = &adev->dev; > + } else { > + struct platform_device *pdev = of_find_device_by_node(np); > + > + if (!pdev) { > + pr_err("Failed to find pdev: %s\n", np->full_name);
Same here.
thanks,
greg k-h
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