> Il giorno 12 mag 2017, alle ore 17:21, Bin Liu <b-liu@xxxxxx> ha scritto: > > […] > > Moreno, would you mind to test the patch below with your modem? > > […] >> >>> 8< -------------------- >>> diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c >>> index 9c7ee26ef388..465281244596 100644 >>> --- a/drivers/usb/musb/musb_dsps.c >>> +++ b/drivers/usb/musb/musb_dsps.c >>> @@ -245,9 +245,14 @@ static int dsps_check_status(struct musb *musb, void *unused) >>> dsps_mod_timer_optional(glue); >>> break; >>> case OTG_STATE_A_WAIT_BCON: >>> + /* keep VBUS on for host-only mode */ >>> + if (musb->port_mode == MUSB_PORT_MODE_HOST) { >>> + dsps_mod_timer_optional(glue); >>> + break; >>> + } >>> musb_writeb(musb->mregs, MUSB_DEVCTL, 0); >>> skip_session = 1; >>> - /* fall */ >>> + /* fall through */ >>> >>> case OTG_STATE_A_IDLE: >>> case OTG_STATE_B_IDLE: Hello Bin, I tested the above patch with my device and it seems to work correctly with the current mainline kernel. I tested it with my “production” kernel as well (4.9.20) but, for it to work, I had to change it slightly. This is what I tested for kernel 4.9.20: --- a/drivers/usb/musb/musb_dsps.c 2017-05-15 08:40:23.000000000 +0200 +++ b/drivers/usb/musb/musb_dsps.c 2017-05-15 08:49:17.000000000 +0200 @@ -213,6 +213,12 @@ static int dsps_check_status(struct musb msecs_to_jiffies(wrp->poll_timeout)); break; case OTG_STATE_A_WAIT_BCON: + /* keep VBUS on for host-only mode */ + if (musb->port_mode == MUSB_PORT_MODE_HOST) { + mod_timer(&glue->timer, jiffies + + msecs_to_jiffies(wrp->poll_timeout)); + break; + } musb_writeb(musb->mregs, MUSB_DEVCTL, 0); skip_session = 1; /* fall */ In this form, it appears to work properly for 4.9.20 too. Best regards, Moreno -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html