* Re: [PATCH] cmd: ums: Set Device Descriptor iSerial based on serial# env variable
2026-06-13 2:54 [PATCH] cmd: ums: Set Device Descriptor iSerial based on serial# env variable Marek Vasut
@ 2026-06-14 10:15 ` Łukasz Majewski
2026-06-15 7:18 ` Mattijs Korpershoek
2026-06-26 13:36 ` Quentin Schulz
2 siblings, 0 replies; 4+ messages in thread
From: Łukasz Majewski @ 2026-06-14 10:15 UTC (permalink / raw)
To: Marek Vasut; +Cc: u-boot, Mattijs Korpershoek, Simon Glass, Tom Rini
On Sat, 13 Jun 2026 04:54:23 +0200
Marek Vasut <marex@nabladev.com> wrote:
> The DFU code currently sets the content of "serial#" environment
> variable into Device Descriptor iSerial field. This is useful when
> there are multiple devices connected to the same host PC and they
> have to be told apart. Replicate the same behavior in the UMS code.
>
> Example without serial# set, which is the original behavior:
> "
> u-boot=> ums 0 mmc 1
> UMS: LUN 0, dev mmc 1, hwpart 0, sector 0x0, count 0x1d5a000
>
> $ dmesg -w
> ...
> usb 5-2.3.7: New USB device found, idVendor=0525, idProduct=a4a5,
> bcdDevice=7e.a7 usb 5-2.3.7: New USB device strings: Mfr=1,
> Product=2, SerialNumber=0 usb 5-2.3.7: Product: USB download gadget
> usb 5-2.3.7: Manufacturer: Vendor
> <------------------------------- NOT HERE
> usb-storage 5-2.3.7:1.0: USB Mass Storage device detected
> ...
>
> $ lsusb -vd 0525:a4a5
>
> Bus 005 Device 051: ID 0525:a4a5 Netchip Technology, Inc. Linux-USB
> File-backed Storage Gadget Negotiated speed: High Speed (480Mbps)
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 0 [unknown]
> bDeviceSubClass 0 [unknown]
> bDeviceProtocol 0
> bMaxPacketSize0 64
> idVendor 0x0525 Netchip Technology, Inc.
> idProduct 0xa4a5 Linux-USB File-backed Storage Gadget
> bcdDevice 7e.a7
> iManufacturer 1 Vendor
> iProduct 2 USB download gadget
> iSerial 0 <------------------------------- NOT HERE
> ...
> "
>
> Example with serial# set to 1234abcd, which is the optional new
> behavior: "
> u-boot=> setenv serial# 1234abcd <------------------------------ HERE
> u-boot=> ums 0 mmc 1
> UMS: LUN 0, dev mmc 1, hwpart 0, sector 0x0, count 0x1d5a000
>
> $ dmesg -w
> ...
> usb 5-2.3.7: New USB device found, idVendor=0525, idProduct=a4a5,
> bcdDevice=7e.a7 usb 5-2.3.7: New USB device strings: Mfr=1,
> Product=2, SerialNumber=3 usb 5-2.3.7: Product: USB download gadget
> usb 5-2.3.7: Manufacturer: Vendor
> usb 5-2.3.7: SerialNumber: 1234abcd <--------------------------- HERE
> usb-storage 5-2.3.7:1.0: USB Mass Storage device detected
> ...
>
> $ lsusb -vd 0525:a4a5
>
> Bus 005 Device 052: ID 0525:a4a5 Netchip Technology, Inc. Linux-USB
> File-backed Storage Gadget Negotiated speed: High Speed (480Mbps)
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 0 [unknown]
> bDeviceSubClass 0 [unknown]
> bDeviceProtocol 0
> bMaxPacketSize0 64
> idVendor 0x0525 Netchip Technology, Inc.
> idProduct 0xa4a5 Linux-USB File-backed Storage Gadget
> bcdDevice 7e.a7
> iManufacturer 1 Vendor
> iProduct 2 USB download gadget
> iSerial 3 1234abcd <-------------------------- HERE
> ...
> "
>
> Signed-off-by: Marek Vasut <marex@nabladev.com>
> ---
> Cc: Lukasz Majewski <lukma@nabladev.com>
> Cc: Mattijs Korpershoek <mkorpershoek@kernel.org>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: u-boot@lists.denx.de
> ---
> cmd/usb_mass_storage.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/cmd/usb_mass_storage.c b/cmd/usb_mass_storage.c
> index e8b87045bdc..335258d7a56 100644
> --- a/cmd/usb_mass_storage.c
> +++ b/cmd/usb_mass_storage.c
> @@ -9,6 +9,7 @@
> #include <blk.h>
> #include <command.h>
> #include <console.h>
> +#include <env.h>
> #include <errno.h>
> #include <g_dnl.h>
> #include <malloc.h>
> @@ -65,7 +66,7 @@ static void ums_fini(void)
>
> static int ums_init(const char *devtype, const char
> *devnums_part_str) {
> - char *s, *t, *devnum_part_str, *name;
> + char *s, *t, *devnum_part_str, *name, *sn;
> struct blk_desc *block_dev;
> struct disk_partition info;
> int partnum;
> @@ -76,6 +77,12 @@ static int ums_init(const char *devtype, const
> char *devnums_part_str) if (!s)
> return -1;
>
> + if (CONFIG_IS_ENABLED(ENV_SUPPORT)) {
> + sn = env_get("serial#");
> + if (sn)
> + g_dnl_set_serialnumber(sn);
> + }
> +
> t = s;
> ums_count = 0;
>
Reviewed-by: Łukasz Majewski <lukma@nabladev.com>
--
Best regards,
Lukasz Majewski
--
Nabla Software Engineering GmbH
HRB 40522 Augsburg
Phone: +49 821 45592596
E-Mail: office@nabladev.com
Managing Director : Stefano Babic
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] cmd: ums: Set Device Descriptor iSerial based on serial# env variable
2026-06-13 2:54 [PATCH] cmd: ums: Set Device Descriptor iSerial based on serial# env variable Marek Vasut
2026-06-14 10:15 ` Łukasz Majewski
@ 2026-06-15 7:18 ` Mattijs Korpershoek
2026-06-26 13:36 ` Quentin Schulz
2 siblings, 0 replies; 4+ messages in thread
From: Mattijs Korpershoek @ 2026-06-15 7:18 UTC (permalink / raw)
To: Marek Vasut, u-boot
Cc: Marek Vasut, Lukasz Majewski, Mattijs Korpershoek, Simon Glass,
Tom Rini
Hi Marek,
Thank you for the patch.
On Sat, Jun 13, 2026 at 04:54, Marek Vasut <marex@nabladev.com> wrote:
> The DFU code currently sets the content of "serial#" environment
> variable into Device Descriptor iSerial field. This is useful when
> there are multiple devices connected to the same host PC and they
> have to be told apart. Replicate the same behavior in the UMS code.
>
> Example without serial# set, which is the original behavior:
> "
> u-boot=> ums 0 mmc 1
> UMS: LUN 0, dev mmc 1, hwpart 0, sector 0x0, count 0x1d5a000
>
> $ dmesg -w
> ...
> usb 5-2.3.7: New USB device found, idVendor=0525, idProduct=a4a5, bcdDevice=7e.a7
> usb 5-2.3.7: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> usb 5-2.3.7: Product: USB download gadget
> usb 5-2.3.7: Manufacturer: Vendor
> <------------------------------- NOT HERE
> usb-storage 5-2.3.7:1.0: USB Mass Storage device detected
> ...
>
> $ lsusb -vd 0525:a4a5
>
> Bus 005 Device 051: ID 0525:a4a5 Netchip Technology, Inc. Linux-USB File-backed Storage Gadget
> Negotiated speed: High Speed (480Mbps)
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 0 [unknown]
> bDeviceSubClass 0 [unknown]
> bDeviceProtocol 0
> bMaxPacketSize0 64
> idVendor 0x0525 Netchip Technology, Inc.
> idProduct 0xa4a5 Linux-USB File-backed Storage Gadget
> bcdDevice 7e.a7
> iManufacturer 1 Vendor
> iProduct 2 USB download gadget
> iSerial 0 <------------------------------- NOT HERE
> ...
> "
>
> Example with serial# set to 1234abcd, which is the optional new behavior:
> "
> u-boot=> setenv serial# 1234abcd <------------------------------ HERE
> u-boot=> ums 0 mmc 1
> UMS: LUN 0, dev mmc 1, hwpart 0, sector 0x0, count 0x1d5a000
>
> $ dmesg -w
> ...
> usb 5-2.3.7: New USB device found, idVendor=0525, idProduct=a4a5, bcdDevice=7e.a7
> usb 5-2.3.7: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> usb 5-2.3.7: Product: USB download gadget
> usb 5-2.3.7: Manufacturer: Vendor
> usb 5-2.3.7: SerialNumber: 1234abcd <--------------------------- HERE
> usb-storage 5-2.3.7:1.0: USB Mass Storage device detected
> ...
>
> $ lsusb -vd 0525:a4a5
>
> Bus 005 Device 052: ID 0525:a4a5 Netchip Technology, Inc. Linux-USB File-backed Storage Gadget
> Negotiated speed: High Speed (480Mbps)
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 0 [unknown]
> bDeviceSubClass 0 [unknown]
> bDeviceProtocol 0
> bMaxPacketSize0 64
> idVendor 0x0525 Netchip Technology, Inc.
> idProduct 0xa4a5 Linux-USB File-backed Storage Gadget
> bcdDevice 7e.a7
> iManufacturer 1 Vendor
> iProduct 2 USB download gadget
> iSerial 3 1234abcd <-------------------------- HERE
> ...
> "
>
> Signed-off-by: Marek Vasut <marex@nabladev.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@kernel.org>
> ---
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] cmd: ums: Set Device Descriptor iSerial based on serial# env variable
2026-06-13 2:54 [PATCH] cmd: ums: Set Device Descriptor iSerial based on serial# env variable Marek Vasut
2026-06-14 10:15 ` Łukasz Majewski
2026-06-15 7:18 ` Mattijs Korpershoek
@ 2026-06-26 13:36 ` Quentin Schulz
2 siblings, 0 replies; 4+ messages in thread
From: Quentin Schulz @ 2026-06-26 13:36 UTC (permalink / raw)
To: Marek Vasut, u-boot
Cc: Lukasz Majewski, Mattijs Korpershoek, Simon Glass, Tom Rini
Hi Marek,
On 6/13/26 4:54 AM, Marek Vasut wrote:
> The DFU code currently sets the content of "serial#" environment
> variable into Device Descriptor iSerial field. This is useful when
> there are multiple devices connected to the same host PC and they
> have to be told apart. Replicate the same behavior in the UMS code.
>
> Example without serial# set, which is the original behavior:
> "
> u-boot=> ums 0 mmc 1
> UMS: LUN 0, dev mmc 1, hwpart 0, sector 0x0, count 0x1d5a000
>
> $ dmesg -w
> ...
> usb 5-2.3.7: New USB device found, idVendor=0525, idProduct=a4a5, bcdDevice=7e.a7
> usb 5-2.3.7: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> usb 5-2.3.7: Product: USB download gadget
> usb 5-2.3.7: Manufacturer: Vendor
> <------------------------------- NOT HERE
> usb-storage 5-2.3.7:1.0: USB Mass Storage device detected
> ...
>
> $ lsusb -vd 0525:a4a5
>
> Bus 005 Device 051: ID 0525:a4a5 Netchip Technology, Inc. Linux-USB File-backed Storage Gadget
> Negotiated speed: High Speed (480Mbps)
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 0 [unknown]
> bDeviceSubClass 0 [unknown]
> bDeviceProtocol 0
> bMaxPacketSize0 64
> idVendor 0x0525 Netchip Technology, Inc.
> idProduct 0xa4a5 Linux-USB File-backed Storage Gadget
> bcdDevice 7e.a7
> iManufacturer 1 Vendor
> iProduct 2 USB download gadget
> iSerial 0 <------------------------------- NOT HERE
> ...
> "
>
> Example with serial# set to 1234abcd, which is the optional new behavior:
> "
> u-boot=> setenv serial# 1234abcd <------------------------------ HERE
> u-boot=> ums 0 mmc 1
> UMS: LUN 0, dev mmc 1, hwpart 0, sector 0x0, count 0x1d5a000
>
> $ dmesg -w
> ...
> usb 5-2.3.7: New USB device found, idVendor=0525, idProduct=a4a5, bcdDevice=7e.a7
> usb 5-2.3.7: New USB device strings: Mfr=1, Product=2, SerialNumber=3
> usb 5-2.3.7: Product: USB download gadget
> usb 5-2.3.7: Manufacturer: Vendor
> usb 5-2.3.7: SerialNumber: 1234abcd <--------------------------- HERE
> usb-storage 5-2.3.7:1.0: USB Mass Storage device detected
> ...
>
> $ lsusb -vd 0525:a4a5
>
> Bus 005 Device 052: ID 0525:a4a5 Netchip Technology, Inc. Linux-USB File-backed Storage Gadget
> Negotiated speed: High Speed (480Mbps)
> Device Descriptor:
> bLength 18
> bDescriptorType 1
> bcdUSB 2.00
> bDeviceClass 0 [unknown]
> bDeviceSubClass 0 [unknown]
> bDeviceProtocol 0
> bMaxPacketSize0 64
> idVendor 0x0525 Netchip Technology, Inc.
> idProduct 0xa4a5 Linux-USB File-backed Storage Gadget
> bcdDevice 7e.a7
> iManufacturer 1 Vendor
> iProduct 2 USB download gadget
> iSerial 3 1234abcd <-------------------------- HERE
> ...
> "
>
> Signed-off-by: Marek Vasut <marex@nabladev.com>
> ---
> Cc: Lukasz Majewski <lukma@nabladev.com>
> Cc: Mattijs Korpershoek <mkorpershoek@kernel.org>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Tom Rini <trini@konsulko.com>
> Cc: u-boot@lists.denx.de
> ---
> cmd/usb_mass_storage.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/cmd/usb_mass_storage.c b/cmd/usb_mass_storage.c
> index e8b87045bdc..335258d7a56 100644
> --- a/cmd/usb_mass_storage.c
> +++ b/cmd/usb_mass_storage.c
> @@ -9,6 +9,7 @@
> #include <blk.h>
> #include <command.h>
> #include <console.h>
> +#include <env.h>
> #include <errno.h>
> #include <g_dnl.h>
> #include <malloc.h>
> @@ -65,7 +66,7 @@ static void ums_fini(void)
>
> static int ums_init(const char *devtype, const char *devnums_part_str)
> {
> - char *s, *t, *devnum_part_str, *name;
> + char *s, *t, *devnum_part_str, *name, *sn;
Reduce the scope of the variable by declaring this variable in the
if-block? I find it easier follow code this way. Additionally, I'm
assuming we could get a "variable defined but never used" kinda warning
if ENV_SUPPORT is not selected?
I don't know anything about USB, but I'm a bit puzzled by the choice of
location, as the DFU, fastboot and rockusb USB gadget drivers are
setting this in their bind function... shouldn't this be added in
drivers/usb/gadget/f_mass_storage.c:fsg_bind() instead to match? I'm
thinking, if someone programmatically configures the UMS gadget driver
without going through the CLI, they probably would be missing this as well?
Cheers,
Quentin
^ permalink raw reply [flat|nested] 4+ messages in thread