Hi Andrew,

Am 16.11.2017 um 19:32 schrieb Andrew F. Davis [off-list ref]:

On 11/16/2017 12:18 PM, H. Nikolaus Schaller wrote:

quoted

quoted

Am 16.11.2017 um 18:08 schrieb Andrew F. Davis [off-list ref]:

On 11/16/2017 10:10 AM, H. Nikolaus Schaller wrote:

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Hi Andrew,

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Am 16.11.2017 um 16:53 schrieb Andrew F. Davis [off-list ref]:

On 11/16/2017 07:43 AM, H. Nikolaus Schaller wrote:

quoted

quoted

Am 16.11.2017 um 13:32 schrieb Tomi Valkeinen [off-list ref]:

On 16/11/17 10:50, H. Nikolaus Schaller wrote:

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The vendor name was "toppoly" but other panels and the vendor list
have defined it as "tpo". So let's fix it in driver and bindings.

Signed-off-by: H. Nikolaus Schaller <redacted>
---

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-MODULE_ALIAS("spi:toppoly,td028ttec1");
+MODULE_ALIAS("spi:tpo,td028ttec1");

Doesn't this mean that the module won't load if you have old bindings?

Hm.

Well, I think it can load but doesn't automatically from DT strings which might
be unexpected.

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Can't we have two module aliases?

I think we can. Just a random example:
https://elixir.free-electrons.com/linux/latest/source/drivers/w1/slaves/w1_therm.c#L754

So we should keep both.

Even better would be to drop both MODULE_ALIAS and let the
MODULE_DEVICE_TABLE macro define them for your from the SPI id table.

Why would that be better?

MODULE_ALIAS is ugly, you already have a table (usually) of device names
that are supported by the driver, the module aliases should be generated
from that table. This also keeps supported device list in one place.

quoted

As far as I see it will need more code and changes than adding one line of
MODULE_ALIAS.

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Although it doesn't look like this driver has an SPI id table, you
should probably add one, I be interested to see if this module is always
being matched through the "spi" or the "of" alias..

Could you please propose how that code should look like, so that I can test?

Sure,

start with
$ udevadm monitor
and see what string the kernel is looking for when trying to find a
module for this device.

Well, the module is loaded automatically from DT at boot time well before
I can start udevadm. So that is the most tricky part to setup the system
to suppress this...

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If it is only ever looking for "of:toppoly,td028ttec1", then you can
drop the MODULE_ALIAS and be done as it was never getting used anyway.

Since it is an SPI client, I am sure it looks for "spi:something.

quoted

What I expect though is "spi:toppoly,td028ttec1", in which case you
should add

static const struct spi_device_id td028ttec1_ids[] = {
	{ "toppoly,td028ttec1", 0 },
	{ "tpo,td028ttec1", 0},
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(spi, td028ttec1_ids);

We already have a static const struct of_device_id td028ttec1_of_match[]
table with the same information.

So we still have two places to keep in sync.

Or can we remove the td028ttec1_of_match[]? AFAIK not.

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link to it in the td028ttec1_spi_driver struct:
.id_table = td028ttec1_ids,

Then test again to see that the module still loads with the new and old
DT string.

In total I am not really convinced that adding 7 lines of code is better
than one (the "tpo," alias) that is tested and works...

And it looks like a lot of unplanned code testing for me which takes more
than 5 minutes :)

So I'd prefer to leave that exercise of fixing the MODULE_ALIAS/DEVICE_TABLE
to someone else...

That's fine, someday I'll probably get some script to do this for all
the drivers that still have MODULE_ALIAS and an existing table.

That would be cool!

On a second thought, I think there is a quick experiment for this driver
not needing to monitor events.

1st attempt: remove ALIASES => if it still loads it would be fine
2nd attempt: add your id table => if it loads again, it is fine
if not, let's keep ALIASES.

Maybe I can try tomorrow.

BR and thanks,
Nikolaus

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BR and thanks,
Nikolaus

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Andrew

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BR and thanks,
Nikolaus Schaller

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Should I submit a new version?

BR,
Nikolaus

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