From: gregkh@linuxfoundation•org (Greg Kroah-Hartman)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v6 0/22] On-demand device probing
Date: Sat, 26 Sep 2015 12:22:18 -0700 [thread overview]
Message-ID: <20150926192218.GA15657@kroah.com> (raw)
In-Reply-To: <5606E120.3070305@kernel.org>
On Sat, Sep 26, 2015 at 01:17:04PM -0500, Rob Herring wrote:
> On 09/21/2015 09:02 AM, Tomeu Vizoso wrote:
> > Hello,
> >
> > I have a problem with the panel on my Tegra Chromebook taking longer
> > than expected to be ready during boot (St?phane Marchesin reported what
> > is basically the same issue in [0]), and have looked into ordered
> > probing as a better way of solving this than moving nodes around in the
> > DT or playing with initcall levels and linking order.
> >
> > While reading the thread [1] that Alexander Holler started with his
> > series to make probing order deterministic, it occurred to me that it
> > should be possible to achieve the same by probing devices as they are
> > referenced by other devices.
> >
> > This basically reuses the information that is already implicit in the
> > probe() implementations, saving us from refactoring existing drivers or
> > adding information to DTBs.
> >
> > During review of v1 of this series Linus Walleij suggested that it
> > should be the device driver core to make sure that dependencies are
> > ready before probing a device. I gave this idea a try [2] but Mark Brown
> > pointed out to the logic duplication between the resource acquisition
> > and dependency discovery code paths (though I think it's fairly minor).
> >
> > To address that code duplication I experimented with Arnd's devm_probe
> > [3] concept of having drivers declare their dependencies instead of
> > acquiring them during probe, and while it worked [4], I don't think we
> > end up winning anything when compared to just probing devices on-demand
> > from resource getters.
> >
> > One remaining objection is to the "sprinkling" of calls to
> > of_device_probe() in the resource getters of each subsystem, but I think
> > it's the right thing to do given that the storage of resources is
> > currently subsystem-specific.
> >
> > We could avoid the above by moving resource storage into the core, but I
> > don't think there's a compelling case for that.
> >
> > I have tested this on boards with Tegra, iMX.6, Exynos, Rockchip and
> > OMAP SoCs, and these patches were enough to eliminate all the deferred
> > probes (except one in PandaBoard because omap_dma_system doesn't have a
> > firmware node as of yet).
> >
> > Have submitted a branch [5][6][7] with these patches on top of today's
> > linux-next (20150921) to kernelci.org and I don't see any issues that
> > could be caused by them.
> >
> > With this series I get the kernel to output to the panel in 0.5s,
> > instead of 2.8s.
>
> I think we're pretty close other than some minor comments. I would like
> to see ack's from Greg and some reviewed-bys from others. The subsystem
> changes are minor and there has been plenty of chance to comment, so I
> don't think acks from all subsystems are needed.
>
> Your branch is based on -next. Is there any dependence on something in
> -next? I want to get this into -next soon, but need a branch not based
> on -next. Please send me a pull request with the collected acks and
> minor comments I have addressed.
Let me review this on Monday and I'll let you know...
thanks,
greg k-h
next prev parent reply other threads:[~2015-09-26 19:22 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-21 14:02 [PATCH v6 0/22] On-demand device probing Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 01/22] driver core: handle -EPROBE_DEFER from bus_type.match() Tomeu Vizoso
2015-10-22 1:00 ` Rafael J. Wysocki
2015-09-21 14:02 ` [PATCH v6 02/22] ARM: amba: Move reading of periphid to amba_match() Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 03/22] of/platform: Point to struct device from device node Tomeu Vizoso
2015-09-22 0:39 ` Rob Herring
2015-09-22 6:45 ` Tomeu Vizoso
2015-10-22 1:02 ` Rafael J. Wysocki
2015-10-22 13:01 ` Tomeu Vizoso
2015-10-24 13:57 ` Rafael J. Wysocki
2015-10-27 14:48 ` Tomeu Vizoso
2015-10-27 15:43 ` Rafael J. Wysocki
2015-10-27 21:24 ` Rob Herring
2015-09-21 14:02 ` [PATCH v6 04/22] of: add function to allow probing a device from a OF node Tomeu Vizoso
2015-10-22 1:06 ` Rafael J. Wysocki
2015-10-22 13:03 ` Tomeu Vizoso
2015-10-22 23:54 ` Mark Brown
2015-10-24 14:28 ` Rafael J. Wysocki
2015-10-24 13:55 ` Rafael J. Wysocki
2015-10-24 20:09 ` Rob Herring
2015-10-26 0:13 ` Mark Brown
2015-10-26 0:15 ` Dmitry Torokhov
2015-10-26 2:48 ` Rafael J. Wysocki
2015-10-26 3:09 ` Mark Brown
2015-10-26 8:16 ` Geert Uytterhoeven
2015-10-27 14:46 ` Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 05/22] gpio: Probe GPIO drivers on demand Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 06/22] gpio: Probe pinctrl devices " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 07/22] regulator: core: Remove regulator_list Tomeu Vizoso
2015-09-21 19:38 ` Mark Brown
2015-09-22 7:21 ` Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 08/22] regulator: core: Probe regulators on demand Tomeu Vizoso
2015-09-21 19:39 ` Mark Brown
2015-09-21 14:02 ` [PATCH v6 09/22] drm: Probe panels " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 10/22] drm/tegra: Probe dpaux devices " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 11/22] i2c: core: Probe i2c adapters and " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 12/22] pwm: Probe PWM chip " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 13/22] backlight: Probe backlight " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 14/22] usb: phy: Probe phy " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 15/22] clk: Probe clk providers " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 16/22] pinctrl: Probe pinctrl devices " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 17/22] phy: core: Probe phy providers " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 18/22] dma: of: Probe DMA controllers " Tomeu Vizoso
2015-09-21 14:02 ` [PATCH v6 19/22] power-supply: Probe power supplies " Tomeu Vizoso
2015-09-21 14:03 ` [PATCH v6 20/22] driver core: Allow deferring probes until late init Tomeu Vizoso
2015-09-26 18:15 ` Rob Herring
2015-09-29 8:05 ` Tomeu Vizoso
2015-09-29 16:58 ` Rob Herring
2015-09-21 14:03 ` [PATCH v6 21/22] driver core: Start processing deferred probes earlier Tomeu Vizoso
2015-10-05 23:52 ` Frank Rowand
2015-10-06 2:49 ` Rob Herring
2015-10-06 10:45 ` Mark Brown
2015-09-21 14:03 ` [PATCH v6 22/22] of/platform: Defer probes of registered devices Tomeu Vizoso
2015-10-21 5:54 ` Scott Wood
2015-10-21 13:44 ` Rob Herring
2015-10-21 22:51 ` Scott Wood
2015-10-22 13:04 ` Tomeu Vizoso
2015-10-22 21:27 ` Scott Wood
2015-10-24 13:51 ` Rafael J. Wysocki
2015-10-28 14:40 ` Tomeu Vizoso
2015-10-29 4:17 ` Rob Herring
2015-10-29 16:06 ` Scott Wood
2015-10-22 0:34 ` Michael Ellerman
2015-09-26 18:17 ` [PATCH v6 0/22] On-demand device probing Rob Herring
2015-09-26 19:22 ` Greg Kroah-Hartman [this message]
2015-09-30 10:09 ` Tomeu Vizoso
2015-09-30 10:23 ` Greg Kroah-Hartman
2015-09-29 8:08 ` Tomeu Vizoso
2015-10-13 19:57 ` Tomeu Vizoso
2015-10-13 21:21 ` Rob Herring
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