| Message ID | 20210920124141.1166544-4-pan@semihalf.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add support for the Mercury+ AA1 module | expand |
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
On Tue, 2021-10-05 at 13:12 +0200, Paweł Anikiel wrote: > 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. Ah, right, those call of_reset_control_get() from TIMER_OF_DECLARE(). Thank you, I'll apply this to reset/fixes. regards Philipp
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 >>
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);
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(+)