[PATCH 0/2] usb: gadget: dwc2: Prepare for UDC core migration

[PATCH 0/2] usb: gadget: dwc2: Prepare for UDC core migration

[Mattijs Korpershoek]

Jens Wiklander started to migrate the DWC3 driver to a more recent
version of linux (v6.16) [1].

This migration also updates the UDC core and most notably how drivers
perform their endpoint matching.

While testing Jens' series on a Khadas VIM3 board, I reported [2] that
I can no longer bind the fastboot gadget to the dwc2 otg driver.

This series aims to fix the problems I've reported.
They can be applied to master/next (as they should not break
anything with the current UDC core). They can also be applied after we
merge Jens' work.

It has been tested on khadas-vim3_android_defconfig with the next branch
using base commit e800cc67f5b6 ("mtd: spi-nor: Add gd55lb02gf chips")

"""
U-Boot 2026.07-rc5-g89106934d3fb (Jul 03 2026 - 15:16:29 +0200) khadas-vim3

Model: Khadas VIM3
SoC:   Amlogic Meson G12B (A311D) Revision 29:b (10:2)
DRAM:  2 GiB (total 3.8 GiB)
Core:  408 devices, 37 uclasses, devicetree: separate
MMC:   mmc@ffe03000: 0, mmc@ffe05000: 1, mmc@ffe07000: 2
MMC Device -1 not foundm MMC...
*** Warning - No MMC card found, using default environment

In:    usbkbd,serial
Out:   vidconsole,serial
Err:   vidconsole,serial
Net:   eth0: ethernet@ff3f0000

Hit any key to stop autoboot: 0
=> fastboot usb 0
crq->brequest:0x0
"""

[1] https://lore.kernel.org/u-boot/20260629084507.3254232-1-jens.wiklander@linaro.org/
[2] https://lore.kernel.org/u-boot/87v7az6l03.fsf@kernel.org/

Signed-off-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
---
Mattijs Korpershoek (2):
      usb: gadget: dwc2: Use usb_ep_set_maxpacket_limit() for fifo sizes
      usb: gadget: dwc2: Set endpoint capabilities via .caps field

 drivers/usb/gadget/dwc2_udc_otg.c | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)
---
base-commit: e800cc67f5b6cb50a20f37c993ec1cd4063bdbd3
change-id: 20260703-usb-prep-dwc3-sync-f564883ebd14

Best regards,
--  
Mattijs Korpershoek <mkorpershoek@kernel.org>

[PATCH 1/2] usb: gadget: dwc2: Use usb_ep_set_maxpacket_limit() for fifo sizes

[Mattijs Korpershoek]

More recent versions of usb_ep_autoconfig() use the maxpacket_limit
field from struct usb_ep.

This field has been introduced in the linux kernel via commit
e117e742d310 ("usb: gadget: add "maxpacket_limit" field to struct usb_ep")
And has been ported to U-Boot via commit
747a0a5b387f ("usb: dwc3: gadget: make dwc3 gadget build in uboot")

However, the dwc2 gadget driver was not converted to use
usb_ep_set_maxpacket_limit().
This is harmless for now, but the driver will break once
usb_ep_autoconfig() is updated to a more recent version.

Set maxpacket_limit via the recommended helper function to prepare for
a core gadget update.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
---
 drivers/usb/gadget/dwc2_udc_otg.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/dwc2_udc_otg.c b/drivers/usb/gadget/dwc2_udc_otg.c
index e475b14b9ac3..9c85383fd62a 100644
--- a/drivers/usb/gadget/dwc2_udc_otg.c
+++ b/drivers/usb/gadget/dwc2_udc_otg.c
@@ -828,7 +828,6 @@ static struct dwc2_udc memory = {
 		.ep = {
 			.name = ep0name,
 			.ops = &dwc2_ep_ops,
-			.maxpacket = EP0_FIFO_SIZE,
 		},
 		.dev = &memory,
 
@@ -843,7 +842,6 @@ static struct dwc2_udc memory = {
 		.ep = {
 			.name = "ep1in-bulk",
 			.ops = &dwc2_ep_ops,
-			.maxpacket = EP_FIFO_SIZE,
 		},
 		.dev = &memory,
 
@@ -858,7 +856,6 @@ static struct dwc2_udc memory = {
 		.ep = {
 			.name = "ep2out-bulk",
 			.ops = &dwc2_ep_ops,
-			.maxpacket = EP_FIFO_SIZE,
 		},
 		.dev = &memory,
 
@@ -873,7 +870,6 @@ static struct dwc2_udc memory = {
 		.ep = {
 			.name = "ep3in-int",
 			.ops = &dwc2_ep_ops,
-			.maxpacket = EP_FIFO_SIZE,
 		},
 		.dev = &memory,
 
@@ -893,6 +889,7 @@ int dwc2_udc_probe(struct dwc2_plat_otg_data *pdata)
 {
 	struct dwc2_udc *dev = &memory;
 	int retval = 0;
+	int i;
 
 	debug("%s: %p\n", __func__, pdata);
 
@@ -909,6 +906,10 @@ int dwc2_udc_probe(struct dwc2_plat_otg_data *pdata)
 
 	the_controller = dev;
 
+	usb_ep_set_maxpacket_limit(&dev->ep[0].ep, EP0_FIFO_SIZE);
+	for (i = 1; i < DWC2_MAX_ENDPOINTS; i++)
+		usb_ep_set_maxpacket_limit(&dev->ep[i].ep, EP_FIFO_SIZE);
+
 	usb_ctrl = memalign(CONFIG_SYS_CACHELINE_SIZE,
 			    ROUND(sizeof(struct usb_ctrlrequest),
 				  CONFIG_SYS_CACHELINE_SIZE));

-- 
2.54.0

Re: [PATCH 1/2] usb: gadget: dwc2: Use usb_ep_set_maxpacket_limit() for fifo sizes

[Ilias Apalodimas]

Not really an expert on USB but this seems reasonable

On Fri, 3 Jul 2026 at 16:29, Mattijs Korpershoek <mkorpershoek@kernel.org>
wrote:

> More recent versions of usb_ep_autoconfig() use the maxpacket_limit
> field from struct usb_ep.
>
> This field has been introduced in the linux kernel via commit
> e117e742d310 ("usb: gadget: add "maxpacket_limit" field to struct usb_ep")
> And has been ported to U-Boot via commit
> 747a0a5b387f ("usb: dwc3: gadget: make dwc3 gadget build in uboot")
>
> However, the dwc2 gadget driver was not converted to use
> usb_ep_set_maxpacket_limit().
> This is harmless for now, but the driver will break once
> usb_ep_autoconfig() is updated to a more recent version.
>
> Set maxpacket_limit via the recommended helper function to prepare for
> a core gadget update.
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
> ---
>

 Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

>  drivers/usb/gadget/dwc2_udc_otg.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/gadget/dwc2_udc_otg.c
> b/drivers/usb/gadget/dwc2_udc_otg.c
> index e475b14b9ac3..9c85383fd62a 100644
> --- a/drivers/usb/gadget/dwc2_udc_otg.c
> +++ b/drivers/usb/gadget/dwc2_udc_otg.c
> @@ -828,7 +828,6 @@ static struct dwc2_udc memory = {
>                 .ep = {
>                         .name = ep0name,
>                         .ops = &dwc2_ep_ops,
> -                       .maxpacket = EP0_FIFO_SIZE,
>                 },
>                 .dev = &memory,
>
> @@ -843,7 +842,6 @@ static struct dwc2_udc memory = {
>                 .ep = {
>                         .name = "ep1in-bulk",
>                         .ops = &dwc2_ep_ops,
> -                       .maxpacket = EP_FIFO_SIZE,
>                 },
>                 .dev = &memory,
>
> @@ -858,7 +856,6 @@ static struct dwc2_udc memory = {
>                 .ep = {
>                         .name = "ep2out-bulk",
>                         .ops = &dwc2_ep_ops,
> -                       .maxpacket = EP_FIFO_SIZE,
>                 },
>                 .dev = &memory,
>
> @@ -873,7 +870,6 @@ static struct dwc2_udc memory = {
>                 .ep = {
>                         .name = "ep3in-int",
>                         .ops = &dwc2_ep_ops,
> -                       .maxpacket = EP_FIFO_SIZE,
>                 },
>                 .dev = &memory,
>
> @@ -893,6 +889,7 @@ int dwc2_udc_probe(struct dwc2_plat_otg_data *pdata)
>  {
>         struct dwc2_udc *dev = &memory;
>         int retval = 0;
> +       int i;
>
>         debug("%s: %p\n", __func__, pdata);
>
> @@ -909,6 +906,10 @@ int dwc2_udc_probe(struct dwc2_plat_otg_data *pdata)
>
>         the_controller = dev;
>
> +       usb_ep_set_maxpacket_limit(&dev->ep[0].ep, EP0_FIFO_SIZE);
> +       for (i = 1; i < DWC2_MAX_ENDPOINTS; i++)
> +               usb_ep_set_maxpacket_limit(&dev->ep[i].ep, EP_FIFO_SIZE);
> +
>         usb_ctrl = memalign(CONFIG_SYS_CACHELINE_SIZE,
>                             ROUND(sizeof(struct usb_ctrlrequest),
>                                   CONFIG_SYS_CACHELINE_SIZE));
>
> --
> 2.54.0
>
>

[PATCH 2/2] usb: gadget: dwc2: Set endpoint capabilities via .caps field

[Mattijs Korpershoek]

Endpoint capabilities can be described via the .caps field of
struct usb_ep since commit
77dcbdf3c1ce ("usb: gadget: Add match_ep() op to usb_gadget_ops")

In linux, the following commit introduces it:
b86f33a3a371 ("usb: gadget: epautoconf: add endpoint capabilities flags verification")

Linux's change also reworks the ep matching function by relying on
these new capabilities instead of guessing based on the endpoint name.

Prepare the dwc2 UDC driver for capability-based matching by adding the
required capabilities for each endpoint.

Signed-off-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
---
 drivers/usb/gadget/dwc2_udc_otg.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/usb/gadget/dwc2_udc_otg.c b/drivers/usb/gadget/dwc2_udc_otg.c
index 9c85383fd62a..570fed347c9e 100644
--- a/drivers/usb/gadget/dwc2_udc_otg.c
+++ b/drivers/usb/gadget/dwc2_udc_otg.c
@@ -828,6 +828,11 @@ static struct dwc2_udc memory = {
 		.ep = {
 			.name = ep0name,
 			.ops = &dwc2_ep_ops,
+			.caps = {
+				.type_control = 1,
+				.dir_in = 1,
+				.dir_out = 1,
+			},
 		},
 		.dev = &memory,
 
@@ -842,6 +847,10 @@ static struct dwc2_udc memory = {
 		.ep = {
 			.name = "ep1in-bulk",
 			.ops = &dwc2_ep_ops,
+			.caps = {
+				.type_bulk = 1,
+				.dir_in = 1,
+			},
 		},
 		.dev = &memory,
 
@@ -856,6 +865,10 @@ static struct dwc2_udc memory = {
 		.ep = {
 			.name = "ep2out-bulk",
 			.ops = &dwc2_ep_ops,
+			.caps = {
+				.type_bulk = 1,
+				.dir_out = 1,
+			},
 		},
 		.dev = &memory,
 
@@ -870,6 +883,10 @@ static struct dwc2_udc memory = {
 		.ep = {
 			.name = "ep3in-int",
 			.ops = &dwc2_ep_ops,
+			.caps = {
+				.type_int = 1,
+				.dir_in = 1,
+			},
 		},
 		.dev = &memory,
 

-- 
2.54.0

Re: [PATCH 2/2] usb: gadget: dwc2: Set endpoint capabilities via .caps field

[Ilias Apalodimas]

On Fri, 3 Jul 2026 at 16:29, Mattijs Korpershoek
<mkorpershoek@kernel.org> wrote:
>
> Endpoint capabilities can be described via the .caps field of
> struct usb_ep since commit
> 77dcbdf3c1ce ("usb: gadget: Add match_ep() op to usb_gadget_ops")
>
> In linux, the following commit introduces it:
> b86f33a3a371 ("usb: gadget: epautoconf: add endpoint capabilities flags verification")
>
> Linux's change also reworks the ep matching function by relying on
> these new capabilities instead of guessing based on the endpoint name.
>
> Prepare the dwc2 UDC driver for capability-based matching by adding the
> required capabilities for each endpoint.
>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
> ---

Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

>  drivers/usb/gadget/dwc2_udc_otg.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/drivers/usb/gadget/dwc2_udc_otg.c b/drivers/usb/gadget/dwc2_udc_otg.c
> index 9c85383fd62a..570fed347c9e 100644
> --- a/drivers/usb/gadget/dwc2_udc_otg.c
> +++ b/drivers/usb/gadget/dwc2_udc_otg.c
> @@ -828,6 +828,11 @@ static struct dwc2_udc memory = {
>                 .ep = {
>                         .name = ep0name,
>                         .ops = &dwc2_ep_ops,
> +                       .caps = {
> +                               .type_control = 1,
> +                               .dir_in = 1,
> +                               .dir_out = 1,
> +                       },
>                 },
>                 .dev = &memory,
>
> @@ -842,6 +847,10 @@ static struct dwc2_udc memory = {
>                 .ep = {
>                         .name = "ep1in-bulk",
>                         .ops = &dwc2_ep_ops,
> +                       .caps = {
> +                               .type_bulk = 1,
> +                               .dir_in = 1,
> +                       },
>                 },
>                 .dev = &memory,
>
> @@ -856,6 +865,10 @@ static struct dwc2_udc memory = {
>                 .ep = {
>                         .name = "ep2out-bulk",
>                         .ops = &dwc2_ep_ops,
> +                       .caps = {
> +                               .type_bulk = 1,
> +                               .dir_out = 1,
> +                       },
>                 },
>                 .dev = &memory,
>
> @@ -870,6 +883,10 @@ static struct dwc2_udc memory = {
>                 .ep = {
>                         .name = "ep3in-int",
>                         .ops = &dwc2_ep_ops,
> +                       .caps = {
> +                               .type_int = 1,
> +                               .dir_in = 1,
> +                       },
>                 },
>                 .dev = &memory,
>
>
> --
> 2.54.0
>

Re: [PATCH 0/2] usb: gadget: dwc2: Prepare for UDC core migration

[Mattijs Korpershoek via U-Boot]

Hi,

On Fri, 03 Jul 2026 15:29:35 +0200, Mattijs Korpershoek wrote:
> Jens Wiklander started to migrate the DWC3 driver to a more recent
> version of linux (v6.16) [1].
> 
> This migration also updates the UDC core and most notably how drivers
> perform their endpoint matching.
> 
> While testing Jens' series on a Khadas VIM3 board, I reported [2] that
> I can no longer bind the fastboot gadget to the dwc2 otg driver.
> 
> [...]

Thanks, Applied to https://source.denx.de/u-boot/custodians/u-boot-dfu (u-boot-dfu)

[1/2] usb: gadget: dwc2: Use usb_ep_set_maxpacket_limit() for fifo sizes
      https://source.denx.de/u-boot/custodians/u-boot-dfu/-/commit/6f9c431a20627db34e0c41ea865c611f0d2c2016
[2/2] usb: gadget: dwc2: Set endpoint capabilities via .caps field
      https://source.denx.de/u-boot/custodians/u-boot-dfu/-/commit/c5c4cc4c6b9887858e168d5106f8f1d3dfb6c3e8

--
Mattijs

Re: [PATCH 0/2] usb: gadget: dwc2: Prepare for UDC core migration

[Mattijs Korpershoek via U-Boot]

On Wed, Jul 22, 2026 at 08:54, Mattijs Korpershoek <mkorpershoek@kernel.org> wrote:

> Hi,
>
> On Fri, 03 Jul 2026 15:29:35 +0200, Mattijs Korpershoek wrote:
>> Jens Wiklander started to migrate the DWC3 driver to a more recent
>> version of linux (v6.16) [1].
>> 
>> This migration also updates the UDC core and most notably how drivers
>> perform their endpoint matching.
>> 
>> While testing Jens' series on a Khadas VIM3 board, I reported [2] that
>> I can no longer bind the fastboot gadget to the dwc2 otg driver.
>> 
>> [...]
>
> Thanks, Applied to https://source.denx.de/u-boot/custodians/u-boot-dfu (u-boot-dfu)
>
> [1/2] usb: gadget: dwc2: Use usb_ep_set_maxpacket_limit() for fifo sizes
>       https://source.denx.de/u-boot/custodians/u-boot-dfu/-/commit/6f9c431a20627db34e0c41ea865c611f0d2c2016
> [2/2] usb: gadget: dwc2: Set endpoint capabilities via .caps field
>       https://source.denx.de/u-boot/custodians/u-boot-dfu/-/commit/c5c4cc4c6b9887858e168d5106f8f1d3dfb6c3e8

Err, my automation is not up to date.
I can confirm the patches have been applied to the new u-boot location:

https://git.u-boot-project.org/u-boot/custodians/u-boot-dfu/-/commit/6f9c431a20627db34e0c41ea865c611f0d2c2016
https://git.u-boot-project.org/u-boot/custodians/u-boot-dfu/-/commit/c5c4cc4c6b9887858e168d5106f8f1d3dfb6c3e8

>
> --
> Mattijs