Re: [PATCH v3 3/6] dm: core: Support multiple drivers with same compatibles

[Mattijs Korpershoek <mkorpershoek@kernel.org>]

Hi Markus,

Thank you for the patch.

On Wed, Jan 14, 2026 at 09:33, "Markus Schneider-Pargmann (TI.com)" <msp@baylibre.com> wrote:

> Currently once a driver matched the compatible string of a device, other
> drivers are ignored. If the first matching driver returns -ENODEV, no
> other possibly matching drivers are iterated with that compatible of the
> device. Instead the next compatible in the list of compatibles is
> selected, assuming only one driver matches one compatible at a time.
>
> To be able to use the bind function to return -ENODEV and continue
> matching other drivers with the same compatible, move the for loop a bit
> to continue the for loop after -ENODEV was returned. The loop had to be
> adjusted a bit to still support the 'drv' argument properly. Some
> simplifications where done as well.

Nitpick: where -> were.

Please don't do any refactor/tweaks in this patch. drivers/core is
already difficult enough to review without formatting changes (to me at
least)

I see a couple below.

>
> The modification will only add additional loop iterations if -ENODEV is
> returned. Otherwise the exit and continue conditions for the loop stay
> the same and do not cause any additional iterations and should not
> impact performance.
>
> This is required for ti-musb-host and ti-musb-peripheral which both
> match on the same device but differ based on the dr_mode DT property.
> Depending on this property, the driver is either UCLASS_USB or
> UCLASS_USB_GADGET_GENERIc. By checking the DT property in the bind

Nitpick: UCLASS_USB_GADGET_GENERIC (not GENERIc)

> function and returning -ENODEV the other driver can probe instead.
>
> Reviewed-by: Simon Glass <simon.glass@canonical.com>
> Signed-off-by: Markus Schneider-Pargmann (TI.com) <msp@baylibre.com>
> ---
>  drivers/core/lists.c | 65 ++++++++++++++++++++++++++--------------------------
>  1 file changed, 33 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/core/lists.c b/drivers/core/lists.c
> index 9d1ca38212ee7f53b8894f964f096611c8ec20a5..3d9f9bc93954efdd624dddb1833f3a855c3c28de 100644
> --- a/drivers/core/lists.c
> +++ b/drivers/core/lists.c
> @@ -235,50 +235,51 @@ int lists_bind_fdt(struct udevice *parent, ofnode node, struct udevice **devp,
>  		log_debug("   - attempt to match compatible string '%s'\n",
>  			  compat);
>  
> -		id = NULL;
>  		for (entry = driver; entry != driver + n_ents; entry++) {
> +			/* Search for drivers with matching drv or existing of_match */
>  			if (drv) {
>  				if (drv != entry)
>  					continue;
> -				if (!entry->of_match)
> -					break;
> +			} else if (!entry->of_match) {
> +				continue;
>  			}
> -			ret = driver_check_compatible(entry->of_match, &id,
> -						      compat);
> -			if (!ret)
> -				break;
> -		}
> -		if (entry == driver + n_ents)
> -			continue;
>  
> -		if (pre_reloc_only) {
> -			if (!ofnode_pre_reloc(node) &&
> -			    !(entry->flags & DM_FLAG_PRE_RELOC)) {
> -				log_debug("Skipping device pre-relocation\n");
> -				return 0;
> +			id = NULL;
> +			if (entry->of_match) {
> +				ret = driver_check_compatible(entry->of_match, &id,
> +							      compat);
> +				if (ret)
> +					continue;
> +				log_debug("   - found match at driver '%s' for '%s'\n",
> +					  entry->name, id->compatible);
> +			}
> +
> +			if (pre_reloc_only) {
> +				if (!ofnode_pre_reloc(node) &&
> +				    !(entry->flags & DM_FLAG_PRE_RELOC)) {
> +					log_debug("   - Skipping device pre-relocation\n");


This was changed from :

  log_debug("Skipping device pre-relocation\n");

Please move log formatting to a separate, cosmetic patch. This way, this
patch stays purely functional, and simpler.

See: https://docs.u-boot.org/en/latest/develop/sending_patches.html#general-patch-submission-rules


> +					return 0;
> +				}
> +			}
> +
> +			ret = device_bind_with_driver_data(parent, entry, name,
> +							   id ? id->data : 0, node,
> +							   &dev);
> +			if (!drv && ret == -ENODEV) {
> +				log_debug("   - Driver '%s' refuses to bind\n", entry->name);

Same here. We added "   -" to the log, making the diff overly
complicated.

Locally, discarded these message formatting changes and the diff was
much simpler.

Can we please re-submit by moving the formatting changes in a separate
patch?

Thanks
Mattijs