From 6c04cb1a451ad0812b583398352882f7d1e3b41c Mon Sep 17 00:00:00 2001
From: Antonio Galea <antonio.galea@gmail.com>
Date: Thu, 10 Oct 2019 08:26:45 +0200
Subject: [PATCH] USBUS CDC ACM: disable interrupts when using tsrb

---
 sys/usb/usbus/cdc/acm/cdc_acm.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/sys/usb/usbus/cdc/acm/cdc_acm.c b/sys/usb/usbus/cdc/acm/cdc_acm.c
index a132fce5ba..a8e4bcccd9 100644
--- a/sys/usb/usbus/cdc/acm/cdc_acm.c
+++ b/sys/usb/usbus/cdc/acm/cdc_acm.c
@@ -126,11 +126,17 @@ static size_t _gen_full_acm_descriptor(usbus_t *usbus, void *arg)
 /* Submit (ACM interface in) */
 size_t usbus_cdc_acm_submit(usbus_cdcacm_device_t *cdcacm, const uint8_t *buf, size_t len)
 {
+    size_t n;
+    unsigned old;
     if (cdcacm->state != USBUS_CDC_ACM_LINE_STATE_DISCONNECTED) {
-        return tsrb_add(&cdcacm->tsrb, buf, len);
+        old = irq_disable();
+        n = tsrb_add(&cdcacm->tsrb, buf, len);
+        irq_restore(old);
+        return n;
     }
     /* stuff as much data as possible into tsrb, discarding the oldest */
-    size_t n = tsrb_free(&cdcacm->tsrb);
+    old = irq_disable();
+    n = tsrb_free(&cdcacm->tsrb);
     if (len > n) {
         n += tsrb_drop(&cdcacm->tsrb, len - n);
         buf += len - n;
@@ -139,15 +145,16 @@ size_t usbus_cdc_acm_submit(usbus_cdcacm_device_t *cdcacm, const uint8_t *buf, s
     }
     tsrb_add(&cdcacm->tsrb, buf, n);
     /* behave as if everything has been written correctly */
+    irq_restore(old);
     return len;
 }
 
 void usbus_cdc_acm_set_coding_cb(usbus_cdcacm_device_t *cdcacm,
                                  usbus_cdcacm_coding_cb_t coding_cb)
 {
-    irq_disable();
+    unsigned old = irq_disable();
     cdcacm->coding_cb = coding_cb;
-    irq_enable();
+    irq_restore(old);
 }
 
 /* flush event */
@@ -286,6 +293,8 @@ static void _handle_in(usbus_cdcacm_device_t *cdcacm,
         (cdcacm->state != USBUS_CDC_ACM_LINE_STATE_DTE)) {
         return;
     }
+    /* copy at most USBUS_CDC_ACM_BULK_EP_SIZE chars from input into ep->buf */
+    unsigned old = irq_disable();
     while (!tsrb_empty(&cdcacm->tsrb)) {
         int c = tsrb_get_one(&cdcacm->tsrb);
         ep->buf[cdcacm->occupied++] = (uint8_t)c;
@@ -293,6 +302,7 @@ static void _handle_in(usbus_cdcacm_device_t *cdcacm,
             break;
         }
     }
+    irq_restore(old);
     usbdev_ep_ready(ep, cdcacm->occupied);
 }