Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
usb: dwc3: gadget: Reinitiate stream for all host NoStream behavior
There are too many different host behaviors when it comes to NoStream
handling, and not everyone follows the USB and xHCI spec. The DWC3
driver attempts to do some guess work to interop with different hosts,
but it can't cover everything. Let's keep it simple and treat every host
the same: just retry on NoStream after a 100ms of no response delay.
Note that some hosts cannot handle frequent retries. This may affect
performance on certain defective hosts, but NoStream is a rare
occurrence and interoperability is more important.
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/b92ae94c86f01f165d5f178b7767898573b6dc75.1736819308.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
authored by
Thinh Nguyen
and committed by
Greg Kroah-Hartman
dcfe4374
f386bfad
+59
-53
+2
-1
drivers/usb/dwc3/core.h
+2
-1
drivers/usb/dwc3/core.h
···
743
743
*/
744
744
struct dwc3_ep {
745
745
struct usb_ep endpoint;
746
+
struct delayed_work nostream_work;
746
747
struct list_head cancelled_list;
747
748
struct list_head pending_list;
748
749
struct list_head started_list;
···
766
765
#define DWC3_EP_WAIT_TRANSFER_COMPLETE BIT(7)
767
766
#define DWC3_EP_IGNORE_NEXT_NOSTREAM BIT(8)
768
767
#define DWC3_EP_FORCE_RESTART_STREAM BIT(9)
769
-
#define DWC3_EP_FIRST_STREAM_PRIMED BIT(10)
768
+
#define DWC3_EP_STREAM_PRIMED BIT(10)
770
769
#define DWC3_EP_PENDING_CLEAR_STALL BIT(11)
771
770
#define DWC3_EP_TXFIFO_RESIZED BIT(12)
772
771
#define DWC3_EP_DELAY_STOP BIT(13)
+57
-52
drivers/usb/dwc3/gadget.c
+57
-52
drivers/usb/dwc3/gadget.c
···
996
996
997
997
/*
998
998
* All stream eps will reinitiate stream on NoStream
999
-
* rejection until we can determine that the host can
1000
-
* prime after the first transfer.
999
+
* rejection.
1001
1000
*
1002
1001
* However, if the controller is capable of
1003
1002
* TXF_FLUSH_BYPASS, then IN direction endpoints will
···
3299
3300
return dwc3_alloc_trb_pool(dep);
3300
3301
}
3301
3302
3303
+
#define nostream_work_to_dep(w) (container_of(to_delayed_work(w), struct dwc3_ep, nostream_work))
3304
+
static void dwc3_nostream_work(struct work_struct *work)
3305
+
{
3306
+
struct dwc3_ep *dep = nostream_work_to_dep(work);
3307
+
struct dwc3 *dwc = dep->dwc;
3308
+
unsigned long flags;
3309
+
3310
+
spin_lock_irqsave(&dwc->lock, flags);
3311
+
if (dep->flags & DWC3_EP_STREAM_PRIMED)
3312
+
goto out;
3313
+
3314
+
if ((dep->flags & DWC3_EP_IGNORE_NEXT_NOSTREAM) ||
3315
+
(!DWC3_MST_CAPABLE(&dwc->hwparams) &&
3316
+
!(dep->flags & DWC3_EP_WAIT_TRANSFER_COMPLETE)))
3317
+
goto out;
3318
+
/*
3319
+
* If the host rejects a stream due to no active stream, by the
3320
+
* USB and xHCI spec, the endpoint will be put back to idle
3321
+
* state. When the host is ready (buffer added/updated), it will
3322
+
* prime the endpoint to inform the usb device controller. This
3323
+
* triggers the device controller to issue ERDY to restart the
3324
+
* stream. However, some hosts don't follow this and keep the
3325
+
* endpoint in the idle state. No prime will come despite host
3326
+
* streams are updated, and the device controller will not be
3327
+
* triggered to generate ERDY to move the next stream data. To
3328
+
* workaround this and maintain compatibility with various
3329
+
* hosts, force to reinitiate the stream until the host is ready
3330
+
* instead of waiting for the host to prime the endpoint.
3331
+
*/
3332
+
if (DWC3_VER_IS_WITHIN(DWC32, 100A, ANY)) {
3333
+
unsigned int cmd = DWC3_DGCMD_SET_ENDPOINT_PRIME;
3334
+
3335
+
dwc3_send_gadget_generic_command(dwc, cmd, dep->number);
3336
+
} else {
3337
+
dep->flags |= DWC3_EP_DELAY_START;
3338
+
dwc3_stop_active_transfer(dep, true, true);
3339
+
spin_unlock_irqrestore(&dwc->lock, flags);
3340
+
return;
3341
+
}
3342
+
out:
3343
+
dep->flags &= ~DWC3_EP_IGNORE_NEXT_NOSTREAM;
3344
+
spin_unlock_irqrestore(&dwc->lock, flags);
3345
+
}
3346
+
3302
3347
static int dwc3_gadget_init_endpoint(struct dwc3 *dwc, u8 epnum)
3303
3348
{
3304
3349
struct dwc3_ep *dep;
···
3388
3345
INIT_LIST_HEAD(&dep->pending_list);
3389
3346
INIT_LIST_HEAD(&dep->started_list);
3390
3347
INIT_LIST_HEAD(&dep->cancelled_list);
3348
+
INIT_DELAYED_WORK(&dep->nostream_work, dwc3_nostream_work);
3391
3349
3392
3350
dwc3_debugfs_create_endpoint_dir(dep);
3393
3351
···
3788
3744
static void dwc3_gadget_endpoint_stream_event(struct dwc3_ep *dep,
3789
3745
const struct dwc3_event_depevt *event)
3790
3746
{
3791
-
struct dwc3 *dwc = dep->dwc;
3792
-
3793
3747
if (event->status == DEPEVT_STREAMEVT_FOUND) {
3794
-
dep->flags |= DWC3_EP_FIRST_STREAM_PRIMED;
3795
-
goto out;
3748
+
cancel_delayed_work(&dep->nostream_work);
3749
+
dep->flags |= DWC3_EP_STREAM_PRIMED;
3750
+
dep->flags &= ~DWC3_EP_IGNORE_NEXT_NOSTREAM;
3751
+
return;
3796
3752
}
3797
3753
3798
3754
/* Note: NoStream rejection event param value is 0 and not 0xFFFF */
3799
3755
switch (event->parameters) {
3800
3756
case DEPEVT_STREAM_PRIME:
3801
-
/*
3802
-
* If the host can properly transition the endpoint state from
3803
-
* idle to prime after a NoStream rejection, there's no need to
3804
-
* force restarting the endpoint to reinitiate the stream. To
3805
-
* simplify the check, assume the host follows the USB spec if
3806
-
* it primed the endpoint more than once.
3807
-
*/
3808
-
if (dep->flags & DWC3_EP_FORCE_RESTART_STREAM) {
3809
-
if (dep->flags & DWC3_EP_FIRST_STREAM_PRIMED)
3810
-
dep->flags &= ~DWC3_EP_FORCE_RESTART_STREAM;
3811
-
else
3812
-
dep->flags |= DWC3_EP_FIRST_STREAM_PRIMED;
3813
-
}
3814
-
3757
+
cancel_delayed_work(&dep->nostream_work);
3758
+
dep->flags |= DWC3_EP_STREAM_PRIMED;
3759
+
dep->flags &= ~DWC3_EP_IGNORE_NEXT_NOSTREAM;
3815
3760
break;
3816
3761
case DEPEVT_STREAM_NOSTREAM:
3817
-
if ((dep->flags & DWC3_EP_IGNORE_NEXT_NOSTREAM) ||
3818
-
!(dep->flags & DWC3_EP_FORCE_RESTART_STREAM) ||
3819
-
(!DWC3_MST_CAPABLE(&dwc->hwparams) &&
3820
-
!(dep->flags & DWC3_EP_WAIT_TRANSFER_COMPLETE)))
3821
-
break;
3822
-
3823
-
/*
3824
-
* If the host rejects a stream due to no active stream, by the
3825
-
* USB and xHCI spec, the endpoint will be put back to idle
3826
-
* state. When the host is ready (buffer added/updated), it will
3827
-
* prime the endpoint to inform the usb device controller. This
3828
-
* triggers the device controller to issue ERDY to restart the
3829
-
* stream. However, some hosts don't follow this and keep the
3830
-
* endpoint in the idle state. No prime will come despite host
3831
-
* streams are updated, and the device controller will not be
3832
-
* triggered to generate ERDY to move the next stream data. To
3833
-
* workaround this and maintain compatibility with various
3834
-
* hosts, force to reinitiate the stream until the host is ready
3835
-
* instead of waiting for the host to prime the endpoint.
3836
-
*/
3837
-
if (DWC3_VER_IS_WITHIN(DWC32, 100A, ANY)) {
3838
-
unsigned int cmd = DWC3_DGCMD_SET_ENDPOINT_PRIME;
3839
-
3840
-
dwc3_send_gadget_generic_command(dwc, cmd, dep->number);
3841
-
} else {
3842
-
dep->flags |= DWC3_EP_DELAY_START;
3843
-
dwc3_stop_active_transfer(dep, true, true);
3844
-
return;
3845
-
}
3762
+
dep->flags &= ~DWC3_EP_STREAM_PRIMED;
3763
+
if (dep->flags & DWC3_EP_FORCE_RESTART_STREAM)
3764
+
queue_delayed_work(system_wq, &dep->nostream_work,
3765
+
msecs_to_jiffies(100));
3846
3766
break;
3847
3767
}
3848
-
3849
-
out:
3850
-
dep->flags &= ~DWC3_EP_IGNORE_NEXT_NOSTREAM;
3851
3768
}
3852
3769
3853
3770
static void dwc3_endpoint_interrupt(struct dwc3 *dwc,