dwc_otg: remove unnecessary dma-mode channel halts on disconnect interrupt

Host channels are already halted in kill_urbs_in_qh_list() with the
subsequent interrupt processing behaving as if the URB was dequeued
via HCD callback.

There's no need to clobber the host channel registers a second time
as this exposes races between the driver and host channel resulting
in hcd->free_hc_list becoming corrupted.

diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
index 5ec991624c7865901b22ea01b9f2c58c8535ecfd..a2dc6337836b2719f4c954edeeb2a71301931b04 100644 (file)
--- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
+++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
@@ -200,8 +200,6 @@ static void kill_urbs_in_qh_list(dwc_otg_hcd_t * hcd, dwc_list_link_t * qh_list)
                                dwc_otg_hc_halt(hcd->core_if, qh->channel,
                                                DWC_OTG_HC_XFER_URB_DEQUEUE);
                        }
-                       if(microframe_schedule)
-                               hcd->available_host_channels++;
                        qh->channel = NULL;
                }
                dwc_otg_hcd_qh_remove(hcd, qh);
@@ -369,39 +367,11 @@ static int32_t dwc_otg_hcd_disconnect_cb(void *p)
                        }
                }
 
-               for (i = 0; i < num_channels; i++) {
-                       channel = dwc_otg_hcd->hc_ptr_array[i];
-                       if (DWC_CIRCLEQ_EMPTY_ENTRY(channel, hc_list_entry)) {
-                               hc_regs =
-                                   dwc_otg_hcd->core_if->host_if->hc_regs[i];
-                               hcchar.d32 = DWC_READ_REG32(&hc_regs->hcchar);
-                               if (hcchar.b.chen) {
-                                       /* Halt the channel. */
-                                       hcchar.b.chdis = 1;
-                                       DWC_WRITE_REG32(&hc_regs->hcchar,
-                                                       hcchar.d32);
-                               }
-
-                               dwc_otg_hc_cleanup(dwc_otg_hcd->core_if,
-                                                  channel);
-                               DWC_CIRCLEQ_INSERT_TAIL
-                                   (&dwc_otg_hcd->free_hc_list, channel,
-                                    hc_list_entry);
-                               /*
-                                * Added for Descriptor DMA to prevent channel double cleanup
-                                * in release_channel_ddma(). Which called from ep_disable
-                                * when device disconnect.
-                                */
-                               if (dwc_otg_hcd->core_if->dma_desc_enable)
-                                       channel->qh = NULL;
-                       }
-               }
                if(fiq_fsm_enable) {
                        for(i=0; i < 128; i++) {
                                dwc_otg_hcd->hub_port[i] = 0;
                        }
                }
-
        }
 
        if(fiq_enable) {