On Wed, Jun 17, 2026 at 11:19, Mattijs Korpershoek <[email protected]> wrote:
> Hi Patrice, > > Thank you for the patch and for finding this bug. > > On Tue, Jun 16, 2026 at 14:57, Patrice Chotard <[email protected]> > wrote: > >> Issue found with STM32MP157C-DK2 board, first usage of "ums 0 mmc 0" >> is working, but second execution doesn't. The mass storage is not visible >> from host side. >> >> Since commit 59310d1ecb9f ("usb: gadget: introduce 'enabled' flag >> in struct usb_ep"), usb_ep_enable() returns early when ep->enabled is >> already set. >> >> The DWC2 UDC driver reinitializes its endpoint software state in >> udc_reinit(), including descriptor, stopped state and request queues, but >> it leaves the generic usb_ep.enabled flag untouched. After stopping UMS >> once, endpoints can therefore still look enabled to the gadget core even >> though the DWC2 endpoint state has been reset. >> >> On the next "ums 0 mmc 0" run, usb_ep_enable() skips the controller >> enable callback, so the host no longer sees a usable USB mass-storage >> device. >> >> Clear ep->ep.enabled together with the rest of the DWC2 endpoint state so >> each new gadget run programs the hardware endpoints again. >> >> Tested on STM32MP157c-dk2 board. >> >> Fixes: 59310d1ecb9f ("usb: gadget: introduce 'enabled' flag in struct >> usb_ep") >> Signed-off-by: Patrice Chotard <[email protected]> > > I give this some testing and I have curious results. > > With commit a7830e87555a ("Merge branch 'master' of > https://source.denx.de/u-boot/custodians/u-boot-sh";), > > I reproduce this on VIM3 (using configs/khadas-vim3_android_defconfig) > with: > """ > U-Boot 2026.07-rc4-00061-ga7830e87555a (Jun 17 2026 - 11:07:46 +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 > Loading Environment from MMC... Reading from MMC(2)... OK > In: usbkbd,serial > Out: vidconsole,serial > Err: vidconsole,serial > Net: eth0: ethernet@ff3f0000 > > Hit any key to stop autoboot: 0 > => ums 0 mmc 2 > UMS: LUN 0, dev mmc 2, hwpart 0, sector 0x0, count 0x3a3e000 > -crq->brequest:0x0 > \ > CTRL+C - Operation aborted > => > """ > > On host (before interrupting UMS): > $ lsblk /dev/sda > NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS > sda 8:0 1 29.1G 0 disk > > Then we restart UMS: > """ > => ums 0 mmc 2 > UMS: LUN 0, dev mmc 2, hwpart 0, sector 0x0, count 0x3a3e000 > \crq->brequest:0x0 > """ > > On host: > $ lsblk /dev/sda > lsblk: /dev/sda: not a block device > > I can also confirm that your patch solves the issue for me with UMS. > > However, using fastboot (which also binds to the gadget driver, I can't > reproduce this issue): > > """ > U-Boot 2026.07-rc4-00061-ga7830e87555a (Jun 17 2026 - 11:15:24 +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 > Loading Environment from MMC... Reading from MMC(2)... OK > In: usbkbd,serial > Out: vidconsole,serial > Err: vidconsole,serial > Net: eth0: ethernet@ff3f0000 > > On host (before interrupting UMS): > Hit any key to stop autoboot: 0 > => fastboot usb 0 > crq->brequest:0x0 > """ > > On host: > $ fastboot devices > C8631470D063 Android Fastboot > > Then: interrupt with CTRL+C and re-run: > """ > => fastboot usb 0 > crq->brequest:0x0 > """ > > On host: > $ fastboot devices > C8631470D063 Android Fastboot > > This makes be believe that the current patch might not be the right > approach. Could we investigate why it works for fastboot but not for > UMS? > > Maybe the commands have a different teardown mechanism. Some debugging pointed me out to the following patch that's in linux: https://lore.kernel.org/r/[email protected] I've applied that locally and to me it fixes the issue with UMS. I'll send it to the list. > >> --- >> drivers/usb/gadget/dwc2_udc_otg.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/usb/gadget/dwc2_udc_otg.c >> b/drivers/usb/gadget/dwc2_udc_otg.c >> index e475b14b9ac..5752bf3ca70 100644 >> --- a/drivers/usb/gadget/dwc2_udc_otg.c >> +++ b/drivers/usb/gadget/dwc2_udc_otg.c >> @@ -209,6 +209,7 @@ static void udc_reinit(struct dwc2_udc *dev) >> >> ep->desc = 0; >> ep->stopped = 0; >> + ep->ep.enabled = false; >> INIT_LIST_HEAD(&ep->queue); >> ep->pio_irqs = 0; >> } >> >> --- >> base-commit: badd97fe24dfb73b2728c26b433cabe315a27971 >> change-id: 20260616-ums_fix-fad8736154b6 >> >> Best regards, >> -- >> Patrice Chotard <[email protected]>
