From ba1cd9f1b3cd3343dff4663ad1e717e345971827 Mon Sep 17 00:00:00 2001
From: Brian Cully <bjc@kublai.com>
Date: Tue, 24 Sep 2019 10:56:28 -0400
Subject: Reset the USB host driver if an unrecoverable error is found.

---
 src/lib.rs | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 423cb84..122c412 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -54,7 +54,7 @@ enum AttachedState {
 enum SteadyState {
     Configuring,
     Running,
-    Error,
+    ErrorUntil(usize),
 }
 
 #[derive(Clone, Copy, Debug, PartialEq)]
@@ -67,6 +67,10 @@ enum TaskState {
 use core::mem::{self, MaybeUninit};
 use core::ptr;
 
+/// How long to wait after a permanent error before resetting the
+/// host.
+const ERROR_RESET_DELAY: usize = 200;
+
 const MAX_DEVICES: usize = 4;
 struct DeviceTable {
     tbl: [Option<Device>; MAX_DEVICES],
@@ -360,7 +364,9 @@ where
                     Ok(_) => TaskState::Steady(SteadyState::Running),
                     Err(e) => {
                         warn!("Enumeration error: {:?}", e);
-                        TaskState::Steady(SteadyState::Error)
+                        TaskState::Steady(SteadyState::ErrorUntil(
+                            (self.millis)() + ERROR_RESET_DELAY,
+                        ))
                     }
                 }
             }
@@ -372,12 +378,21 @@ where
                         if let DriverError::Permanent(a, _) = e {
                             d.remove_device(a);
                             self.devices.remove(a);
+                            self.task_state = TaskState::Steady(SteadyState::ErrorUntil(
+                                (self.millis)() + ERROR_RESET_DELAY,
+                            ))
                         }
                     }
                 }
             }
 
-            SteadyState::Error => {}
+            // TODO: this is too heavy-handed: resetting the whole
+            // device when only one may be a problem.
+            SteadyState::ErrorUntil(when) => {
+                if (self.millis)() >= when {
+                    self.task_state = TaskState::Detached(DetachedState::Initialize);
+                }
+            }
         }
     }
 
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