From: Mark Brown <broonie@kernel.org>
To: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Tony Lindgren <tony@atomide.com>,
Graeme Gregory <gg@slimlogic.co.uk>,
Liam Girdwood <lgirdwood@gmail.com>, Nishanth Menon <nm@ti.com>,
Linux-OMAP <linux-omap@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Discussions about the Letux Kernel
<letux-kernel@openphoenux.org>,
kernel@pyra-handheld.com,
Peter Ujfalusi <peter.ujfalusi@gmail.com>
Subject: Re: [PATCH] regulator: palmas: set supply_name after registering the regulator
Date: Wed, 30 Jun 2021 13:13:07 +0100 [thread overview]
Message-ID: <20210630121307.GA5106@sirena.org.uk> (raw)
In-Reply-To: <7B58B1BF-9D65-4CEC-B7D1-4EFDB2C0CB4E@goldelico.com>
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On Tue, Jun 29, 2021 at 10:21:45PM +0200, H. Nikolaus Schaller wrote:
> There seems to be a deadlock in probing:
> e.g. ldo3_reg depends on vdds_1v8_main supply
> vdds_1v8_main depends on smps7_reg supply
> smps7_reg depends on vsys_cobra supply
> vsys_cobra depends on nothing
> This would normally lead to a simple chain as you described above. But
> ldo3_reg and smps7_reg share the same driver and can probe successfully or
> fail only in common.
I don't see any deadlock there? Just a straightforward set of
dependencies. Anything circular would clearly be a driver bug.
> Now if ldo3_reg defers probe through the new rule, smps7_reg is never
> probed successfully because it is the same driver. Hence vdds_1v8_main can
> not become available. And the Palmas continues to run in boot initialization
> until some driver (MMC) wants to switch voltages or whatever.
The driver should just register all the DCDCs before the LDOs, then
everything will sort itself out. It's *possible* you might see a system
trying to link things together regulators of the same type but that's
very unusual as it makes the system less efficient.
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next prev parent reply other threads:[~2021-06-30 12:13 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-29 15:24 [PATCH] regulator: palmas: set supply_name after registering the regulator H. Nikolaus Schaller
2021-06-29 15:59 ` Mark Brown
2021-06-29 18:34 ` H. Nikolaus Schaller
2021-06-29 18:56 ` Mark Brown
2021-06-29 20:21 ` H. Nikolaus Schaller
2021-06-29 20:26 ` Graeme Gregory
2021-06-30 12:13 ` Mark Brown [this message]
2021-06-30 12:29 ` H. Nikolaus Schaller
2021-06-30 13:04 ` Mark Brown
2021-06-30 14:43 ` H. Nikolaus Schaller
2021-06-30 16:45 ` Mark Brown
2021-06-30 17:17 ` H. Nikolaus Schaller
2021-06-30 20:08 ` Mark Brown
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