1 From 09648b92a71b03450e9482f0cc5bd22298f78d44 Mon Sep 17 00:00:00 2001
2 From: Jonathan Bell <jonathan@raspberrypi.org>
3 Date: Wed, 8 Jan 2020 12:48:09 +0000
4 Subject: [PATCH] dwc_otg: fiq_fsm: pause when cancelling split
7 Non-periodic splits will DMA to/from the driver-provided transfer_buffer,
8 which may be freed immediately after the dequeue call returns. Block until
9 we know the transfer is complete.
11 A similar delay is needed when cleaning up disconnects, as the FIQ could
12 have started a periodic transfer in the previous microframe to the one
13 that triggered a disconnect.
15 Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
17 drivers/usb/host/dwc_otg/dwc_otg_hcd.c | 33 +++++++++++++++++++++--
18 drivers/usb/host/dwc_otg/dwc_otg_os_dep.h | 1 +
19 2 files changed, 32 insertions(+), 2 deletions(-)
21 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
22 +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
23 @@ -175,6 +175,7 @@ static void kill_urbs_in_qh_list(dwc_otg
24 dwc_list_link_t *qh_item, *qh_tmp;
26 dwc_otg_qtd_t *qtd, *qtd_tmp;
29 DWC_LIST_FOREACH_SAFE(qh_item, qh_tmp, qh_list) {
30 qh = DWC_LIST_ENTRY(qh_item, dwc_otg_qh_t, qh_list_entry);
31 @@ -198,8 +199,17 @@ static void kill_urbs_in_qh_list(dwc_otg
32 qh->channel->halt_status = DWC_OTG_HC_XFER_URB_DEQUEUE;
33 qh->channel->halt_pending = 1;
34 if (hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_TURBO ||
35 - hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_SLEEPING)
36 + hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_SLEEPING)
37 hcd->fiq_state->channel[n].fsm = FIQ_HS_ISOC_ABORTED;
38 + /* We're called from disconnect callback or in the middle of freeing the HCD here,
39 + * so FIQ is disabled, top-level interrupts masked and we're holding the spinlock.
40 + * No further URBs will be submitted, but wait 1 microframe for any previously
41 + * submitted periodic DMA to finish.
48 dwc_otg_hc_halt(hcd->core_if, qh->channel,
49 DWC_OTG_HC_XFER_URB_DEQUEUE);
50 @@ -600,15 +610,34 @@ int dwc_otg_hcd_urb_dequeue(dwc_otg_hcd_
51 /* In FIQ FSM mode, we need to shut down carefully.
52 * The FIQ may attempt to restart a disabled channel */
53 if (fiq_fsm_enable && (hcd->fiq_state->channel[n].fsm != FIQ_PASSTHROUGH)) {
56 + enum fiq_fsm_state state;
59 fiq_fsm_spin_lock(&hcd->fiq_state->lock);
60 qh->channel->halt_status = DWC_OTG_HC_XFER_URB_DEQUEUE;
61 qh->channel->halt_pending = 1;
62 if (hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_TURBO ||
63 - hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_SLEEPING)
64 + hcd->fiq_state->channel[n].fsm == FIQ_HS_ISOC_SLEEPING)
65 hcd->fiq_state->channel[n].fsm = FIQ_HS_ISOC_ABORTED;
66 fiq_fsm_spin_unlock(&hcd->fiq_state->lock);
69 + if (dwc_qh_is_non_per(qh)) {
71 + state = READ_ONCE(hcd->fiq_state->channel[n].fsm);
72 + running = (state != FIQ_NP_SPLIT_DONE) &&
73 + (state != FIQ_NP_SPLIT_LS_ABORTED) &&
74 + (state != FIQ_NP_SPLIT_HS_ABORTED);
80 + DWC_WARN("Timed out waiting for FSM NP transfer to complete on %d",
81 + qh->channel->hc_num);
84 dwc_otg_hc_halt(hcd->core_if, qh->channel,
85 DWC_OTG_HC_XFER_URB_DEQUEUE);
86 --- a/drivers/usb/host/dwc_otg/dwc_otg_os_dep.h
87 +++ b/drivers/usb/host/dwc_otg/dwc_otg_os_dep.h
89 #include <linux/workqueue.h>
90 #include <linux/stat.h>
91 #include <linux/pci.h>
92 +#include <linux/compiler.h>
94 #include <linux/version.h>