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 <[email protected]> --- Cc: Lukasz Majewski <[email protected]> Cc: Mattijs Korpershoek <[email protected]> Cc: Simon Glass <[email protected]> Cc: Tom Rini <[email protected]> Cc: [email protected] --- 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
