From: "Paweł Anikiel" <pan@semihalf.com>
To: Philipp Zabel <p.zabel@pengutronix.de>,
miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com,
robh+dt@kernel.org, arnd@arndb.de, olof@lixom.net,
soc@kernel.org, dinguyen@kernel.org
Cc: linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Tomasz Nowicki <tn@semihalf.com>,
Konrad Adamczyk <ka@semihalf.com>,
Jacek Majkowski <jam@semihalf.com>
Subject: Re: [PATCH 3/3] reset: socfpga: add empty driver allowing consumers to probe
Date: Tue, 5 Oct 2021 13:12:05 +0200 [thread overview]
Message-ID: <CAF9_jYQVpG8imn3zjAGKeZqZqDPtWRYWLQjNSXi2SXjjzAKvfA@mail.gmail.com> (raw)
Message-ID: <20211005111205.yhacoo2AdAdnUkQ86NaPU0ASEexP3rjoqfZSlZF-dlI@z> (raw)
In-Reply-To: <ce254cc123f2809976c2f2404941a9074c458309.camel@pengutronix.de>
On Tue, Oct 5, 2021 at 11:34 AM Philipp Zabel <p.zabel@pengutronix.de> wrote:
>
> Hi Paweł,
>
> On Mon, 2021-09-20 at 14:41 +0200, Paweł Anikiel wrote:
> > The early reset driver doesn't ever probe, which causes consuming
> > devices to be unable to probe. Add an empty driver to set this device
> > as available, allowing consumers to probe.
> >
> > Signed-off-by: Paweł Anikiel <pan@semihalf.com>
> > ---
> > drivers/reset/reset-socfpga.c | 26 ++++++++++++++++++++++++++
> > 1 file changed, 26 insertions(+)
> >
> > diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
> > index 2a72f861f798..8c6492e5693c 100644
> > --- a/drivers/reset/reset-socfpga.c
> > +++ b/drivers/reset/reset-socfpga.c
> > @@ -92,3 +92,29 @@ void __init socfpga_reset_init(void)
> > for_each_matching_node(np, socfpga_early_reset_dt_ids)
> > a10_reset_init(np);
> > }
> > +
> > +/*
> > + * The early driver is problematic, because it doesn't register
> > + * itself as a driver. This causes certain device links to prevent
> > + * consumer devices from probing. The hacky solution is to register
> > + * an empty driver, whose only job is to attach itself to the reset
> > + * manager and call probe.
> > + */
> > +static const struct of_device_id socfpga_reset_dt_ids[] = {
> > + { .compatible = "altr,rst-mgr", },
> > + { /* sentinel */ },
> > +};
> > +
> > +static int reset_simple_probe(struct platform_device *pdev)
> > +{
> > + return 0;
> > +}
> > +
> > +static struct platform_driver reset_socfpga_driver = {
> > + .probe = reset_simple_probe,
> > + .driver = {
> > + .name = "socfpga-reset",
> > + .of_match_table = socfpga_reset_dt_ids,
> > + },
> > +};
> > +builtin_platform_driver(reset_socfpga_driver);
>
> If we can just let devlink delay all consumers until the empty driver is
> probed, does the reset controller have to be registered early at all?
>
> regards
> Philipp
I asked Dinh if the reset controller code needs to be called early:
>That's correct. It's for one of the SP timers.
>
>On 9/16/21 6:13 AM, Paweł Anikiel wrote:
>> Hi,
>>
>> I would like to ask you about the following commit:
>>> commit b3ca9888f35fa6919569cf27c929dc0ac49e9716
>>> Author: Dinh Nguyen <dinguyen@kernel.org>
>>> Date: Tue Nov 13 12:50:48 2018 -0600
>>>
>>> reset: socfpga: add an early reset driver for SoCFPGA
>>>
>>> Create a separate reset driver that uses the reset operations in
>>> reset-simple. The reset driver for the SoCFPGA platform needs to
>>> register early in order to be able bring online timers that needed
>>> early in the kernel bootup.
>>> [...]
>> Which online timers is this commit message referring to? I couldn't find
>> any information about this. Without this patch the kernel seems to work
>> fine on an Arria 10 (with Mercury AA1 module). What's the exact reason
>> a regular platform driver isn't sufficient?
>>
>> Best regards,
>> Paweł
>>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: "Paweł Anikiel" <pan@semihalf.com>
To: Philipp Zabel <p.zabel@pengutronix.de>,
miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com,
robh+dt@kernel.org, arnd@arndb.de, olof@lixom.net,
soc@kernel.org, dinguyen@kernel.org
Cc: linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Tomasz Nowicki <tn@semihalf.com>,
Konrad Adamczyk <ka@semihalf.com>,
Jacek Majkowski <jam@semihalf.com>
Subject: Re: [PATCH 3/3] reset: socfpga: add empty driver allowing consumers to probe
Date: Tue, 5 Oct 2021 13:12:05 +0200 [thread overview]
Message-ID: <CAF9_jYQVpG8imn3zjAGKeZqZqDPtWRYWLQjNSXi2SXjjzAKvfA@mail.gmail.com> (raw)
Message-ID: <20211005111205.wF9DTMTojuk4JpTAzITFpr5a4MynUV1bKYvFX6hKG_4@z> (raw)
In-Reply-To: <ce254cc123f2809976c2f2404941a9074c458309.camel@pengutronix.de>
On Tue, Oct 5, 2021 at 11:34 AM Philipp Zabel <p.zabel@pengutronix.de> wrote:
>
> Hi Paweł,
>
> On Mon, 2021-09-20 at 14:41 +0200, Paweł Anikiel wrote:
> > The early reset driver doesn't ever probe, which causes consuming
> > devices to be unable to probe. Add an empty driver to set this device
> > as available, allowing consumers to probe.
> >
> > Signed-off-by: Paweł Anikiel <pan@semihalf.com>
> > ---
> > drivers/reset/reset-socfpga.c | 26 ++++++++++++++++++++++++++
> > 1 file changed, 26 insertions(+)
> >
> > diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
> > index 2a72f861f798..8c6492e5693c 100644
> > --- a/drivers/reset/reset-socfpga.c
> > +++ b/drivers/reset/reset-socfpga.c
> > @@ -92,3 +92,29 @@ void __init socfpga_reset_init(void)
> > for_each_matching_node(np, socfpga_early_reset_dt_ids)
> > a10_reset_init(np);
> > }
> > +
> > +/*
> > + * The early driver is problematic, because it doesn't register
> > + * itself as a driver. This causes certain device links to prevent
> > + * consumer devices from probing. The hacky solution is to register
> > + * an empty driver, whose only job is to attach itself to the reset
> > + * manager and call probe.
> > + */
> > +static const struct of_device_id socfpga_reset_dt_ids[] = {
> > + { .compatible = "altr,rst-mgr", },
> > + { /* sentinel */ },
> > +};
> > +
> > +static int reset_simple_probe(struct platform_device *pdev)
> > +{
> > + return 0;
> > +}
> > +
> > +static struct platform_driver reset_socfpga_driver = {
> > + .probe = reset_simple_probe,
> > + .driver = {
> > + .name = "socfpga-reset",
> > + .of_match_table = socfpga_reset_dt_ids,
> > + },
> > +};
> > +builtin_platform_driver(reset_socfpga_driver);
>
> If we can just let devlink delay all consumers until the empty driver is
> probed, does the reset controller have to be registered early at all?
>
> regards
> Philipp
I asked Dinh if the reset controller code needs to be called early:
>That's correct. It's for one of the SP timers.
>
>On 9/16/21 6:13 AM, Paweł Anikiel wrote:
>> Hi,
>>
>> I would like to ask you about the following commit:
>>> commit b3ca9888f35fa6919569cf27c929dc0ac49e9716
>>> Author: Dinh Nguyen <dinguyen@kernel.org>
>>> Date: Tue Nov 13 12:50:48 2018 -0600
>>>
>>> reset: socfpga: add an early reset driver for SoCFPGA
>>>
>>> Create a separate reset driver that uses the reset operations in
>>> reset-simple. The reset driver for the SoCFPGA platform needs to
>>> register early in order to be able bring online timers that needed
>>> early in the kernel bootup.
>>> [...]
>> Which online timers is this commit message referring to? I couldn't find
>> any information about this. Without this patch the kernel seems to work
>> fine on an Arria 10 (with Mercury AA1 module). What's the exact reason
>> a regular platform driver isn't sufficient?
>>
>> Best regards,
>> Paweł
>>
WARNING: multiple messages have this Message-ID (diff)
From: "Paweł Anikiel" <pan@semihalf.com>
To: Philipp Zabel <p.zabel@pengutronix.de>,
miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com,
robh+dt@kernel.org, arnd@arndb.de, olof@lixom.net,
soc@kernel.org, dinguyen@kernel.org
Cc: linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Tomasz Nowicki <tn@semihalf.com>,
Konrad Adamczyk <ka@semihalf.com>,
Jacek Majkowski <jam@semihalf.com>
Subject: Re: [PATCH 3/3] reset: socfpga: add empty driver allowing consumers to probe
Date: Tue, 5 Oct 2021 13:12:05 +0200 [thread overview]
Message-ID: <CAF9_jYQVpG8imn3zjAGKeZqZqDPtWRYWLQjNSXi2SXjjzAKvfA@mail.gmail.com> (raw)
Message-ID: <20211005111205.ZiCYCEHJTbQy5jlzp9j7HbbqrXbmvra3jt_qXW4bAwo@z> (raw)
In-Reply-To: <ce254cc123f2809976c2f2404941a9074c458309.camel@pengutronix.de>
On Tue, Oct 5, 2021 at 11:34 AM Philipp Zabel <p.zabel@pengutronix.de> wrote:
>
> Hi Paweł,
>
> On Mon, 2021-09-20 at 14:41 +0200, Paweł Anikiel wrote:
> > The early reset driver doesn't ever probe, which causes consuming
> > devices to be unable to probe. Add an empty driver to set this device
> > as available, allowing consumers to probe.
> >
> > Signed-off-by: Paweł Anikiel <pan@semihalf.com>
> > ---
> > drivers/reset/reset-socfpga.c | 26 ++++++++++++++++++++++++++
> > 1 file changed, 26 insertions(+)
> >
> > diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
> > index 2a72f861f798..8c6492e5693c 100644
> > --- a/drivers/reset/reset-socfpga.c
> > +++ b/drivers/reset/reset-socfpga.c
> > @@ -92,3 +92,29 @@ void __init socfpga_reset_init(void)
> > for_each_matching_node(np, socfpga_early_reset_dt_ids)
> > a10_reset_init(np);
> > }
> > +
> > +/*
> > + * The early driver is problematic, because it doesn't register
> > + * itself as a driver. This causes certain device links to prevent
> > + * consumer devices from probing. The hacky solution is to register
> > + * an empty driver, whose only job is to attach itself to the reset
> > + * manager and call probe.
> > + */
> > +static const struct of_device_id socfpga_reset_dt_ids[] = {
> > + { .compatible = "altr,rst-mgr", },
> > + { /* sentinel */ },
> > +};
> > +
> > +static int reset_simple_probe(struct platform_device *pdev)
> > +{
> > + return 0;
> > +}
> > +
> > +static struct platform_driver reset_socfpga_driver = {
> > + .probe = reset_simple_probe,
> > + .driver = {
> > + .name = "socfpga-reset",
> > + .of_match_table = socfpga_reset_dt_ids,
> > + },
> > +};
> > +builtin_platform_driver(reset_socfpga_driver);
>
> If we can just let devlink delay all consumers until the empty driver is
> probed, does the reset controller have to be registered early at all?
>
> regards
> Philipp
I asked Dinh if the reset controller code needs to be called early:
>That's correct. It's for one of the SP timers.
>
>On 9/16/21 6:13 AM, Paweł Anikiel wrote:
>> Hi,
>>
>> I would like to ask you about the following commit:
>>> commit b3ca9888f35fa6919569cf27c929dc0ac49e9716
>>> Author: Dinh Nguyen <dinguyen@kernel.org>
>>> Date: Tue Nov 13 12:50:48 2018 -0600
>>>
>>> reset: socfpga: add an early reset driver for SoCFPGA
>>>
>>> Create a separate reset driver that uses the reset operations in
>>> reset-simple. The reset driver for the SoCFPGA platform needs to
>>> register early in order to be able bring online timers that needed
>>> early in the kernel bootup.
>>> [...]
>> Which online timers is this commit message referring to? I couldn't find
>> any information about this. Without this patch the kernel seems to work
>> fine on an Arria 10 (with Mercury AA1 module). What's the exact reason
>> a regular platform driver isn't sufficient?
>>
>> Best regards,
>> Paweł
>>
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2021-10-05 10:14 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210920124138.7Rv4Bat-mDXSJL5_d7ykDRJFDCAMP3dSiZm0nDPMaDU@z>
2021-09-20 12:41 ` [PATCH 0/3] Add support for the Mercury+ AA1 module Paweł Anikiel
2021-09-20 12:41 ` Paweł Anikiel
[not found] ` <20210920124139.jQM-Tqzr63A2Hs1WHPqhhGaUuJiNYaCWKRl5YiR4iTA@z>
2021-09-20 12:41 ` [PATCH 1/3] dt-bindings: mtd: spi-nor: add n25q00 schema Paweł Anikiel
2021-09-20 12:41 ` Paweł Anikiel
[not found] ` <20210923165648.FCg577uaG9fWz1MINUjzq_6XdotxOakHUOjndV9cMBM@z>
2021-09-23 16:56 ` Rob Herring
2021-09-23 16:56 ` Rob Herring
[not found] ` <20210923185904.twJ5GB7t8omyZ7RKqA5bcaS2QzsOxfghoI6XXJrCzfc@z>
2021-09-23 18:59 ` Pratyush Yadav
2021-09-23 18:59 ` Pratyush Yadav
[not found] ` <20211005115906.sVeqCk7Lbj-UbEQBqo8aQDAVjC_bmmDQ6QaO3ChH2n4@z>
2021-10-05 11:59 ` Tudor.Ambarus
2021-10-05 11:59 ` Tudor.Ambarus
[not found] ` <20210920124140.RZTw5kTlMXDVKDMnzhD0FZ5oHIQ_cZ6kTSSrKdQw9WU@z>
2021-09-20 12:41 ` [PATCH 2/3] dts: socfpga: Add Mercury+ AA1 devicetree Paweł Anikiel
2021-09-20 12:41 ` Paweł Anikiel
[not found] ` <20210923165624.wCIpZMuEaOTqgzTIVio-auukBwIkYM1Ik1HRSlI8hTg@z>
2021-09-23 16:56 ` Rob Herring
2021-09-23 16:56 ` Rob Herring
[not found] ` <20210920124141.dOhXof_mbq7fNGtevvmYnhhpG15cTTgPtsQcSOqhER8@z>
2021-09-20 12:41 ` [PATCH 3/3] reset: socfpga: add empty driver allowing consumers to probe Paweł Anikiel
2021-09-20 12:41 ` Paweł Anikiel
[not found] ` <20211005093407.6FCAsOZYukqdChGyMhvCtKU-0iQe1qmWgVVlQSxU-40@z>
2021-10-05 9:34 ` Philipp Zabel
2021-10-05 9:34 ` Philipp Zabel
2021-10-05 9:34 ` Philipp Zabel
[not found] ` <20211005111205.yhacoo2AdAdnUkQ86NaPU0ASEexP3rjoqfZSlZF-dlI@z>
2021-10-05 11:12 ` Paweł Anikiel [this message]
[not found] ` <20211005102225.PzZXA7w0Qn5d_3_cHQbe86EPWtaa_CBoQpc89EEeouA@z>
2021-10-05 10:22 ` Philipp Zabel
2021-10-05 10:22 ` Philipp Zabel
2021-10-05 10:22 ` Philipp Zabel
2021-10-05 11:12 ` Paweł Anikiel
2021-10-05 11:12 ` Paweł Anikiel
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