[PATCH v3 3/6] dm: core: Support multiple drivers with same compatibles
Mattijs Korpershoek
mkorpershoek at kernel.org
Fri Jan 16 11:50:39 CET 2026
Hi Markus,
Thank you for the patch.
On Wed, Jan 14, 2026 at 09:33, "Markus Schneider-Pargmann (TI.com)" <msp at 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 at canonical.com>
> Signed-off-by: Markus Schneider-Pargmann (TI.com) <msp at 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
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