[Qemu-devel] [PATCH 3/5] usb-linux.c: somewhat improve some error and debugging messages

[Ian Jackson]

Firstly, always print strerror(errno) (when relevant) rather than
numerical errno.  Numerical errno values are not very useful and the
libc provides us with strerror especially for this purpose.

Secondly, distinguish previously-identical messages relating to
control and data transfers.

Signed-off-by: Ian Jackson <address@hidden>
---
 usb-linux.c |   23 ++++++++++++-----------
 1 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/usb-linux.c b/usb-linux.c
index 3019a13..8498b1d 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -258,7 +258,7 @@ static void async_complete(void *opaque)
                 return;
             }
 
-            dprintf("husb: async. reap urb failed errno %d\n", errno);
+            dprintf("husb: async. reap urb failed: %s\n", strerror(errno));
             return;
         }
 
@@ -302,7 +302,7 @@ static void async_cancel(USBPacket *unused, void *opaque)
 
     int r = ioctl(s->fd, USBDEVFS_DISCARDURB, aurb);
     if (r < 0) {
-        dprintf("husb: async. discard urb failed errno %d\n", errno);
+        dprintf("husb: async. discard urb failed: %s\n", strerror(errno));
     }
 }
 
@@ -444,7 +444,7 @@ static int usb_host_handle_data(USBHostDevice *s, USBPacket 
*p)
 
     aurb = async_alloc();
     if (!aurb) {
-        dprintf("husb: async malloc failed\n");
+        dprintf("husb: async malloc (data) failed\n");
         return USB_RET_NAK;
     }
     aurb->hdev   = s;
@@ -460,8 +460,8 @@ static int usb_host_handle_data(USBHostDevice *s, USBPacket 
*p)
     if (is_halted(s, p->devep)) {
        ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &urb->endpoint);
         if (ret < 0) {
-            dprintf("husb: failed to clear halt. ep 0x%x errno %d\n", 
-                   urb->endpoint, errno);
+            dprintf("husb: failed to clear halt. ep 0x%x: %s\n",
+                   urb->endpoint, strerror(errno));
             return USB_RET_NAK;
         }
         clear_halt(s, p->devep);
@@ -485,7 +485,7 @@ static int usb_host_handle_data(USBHostDevice *s, USBPacket 
*p)
     dprintf("husb: data submit. ep 0x%x len %u aurb %p\n", urb->endpoint, 
p->len, aurb);
 
     if (ret < 0) {
-        dprintf("husb: submit failed. errno %d\n", errno);
+        dprintf("husb: submit data failed: %s\n", strerror(errno));
         async_free(aurb);
 
         switch(errno) {
@@ -522,7 +522,8 @@ static int usb_host_set_config(USBHostDevice *s, int config)
 
     int ret = ioctl(s->fd, USBDEVFS_SETCONFIGURATION, &config);
  
-    dprintf("husb: ctrl set config %d ret %d errno %d\n", config, ret, errno);
+    dprintf("husb: ctrl set config %d ret %d: %s\n", config, ret,
+           ret < 0 ? strerror(errno) : "ok");
     
     if (ret < 0)
         return ctrl_error();
@@ -540,8 +541,8 @@ static int usb_host_set_interface(USBHostDevice *s, int 
iface, int alt)
     si.altsetting = alt;
     ret = ioctl(s->fd, USBDEVFS_SETINTERFACE, &si);
     
-    dprintf("husb: ctrl set iface %d altset %d ret %d errno %d\n", 
-       iface, alt, ret, errno);
+    dprintf("husb: ctrl set iface %d altset %d ret %d: %s\n",
+       iface, alt, ret, ret < 0 ? strerror(errno): "ok");
     
     if (ret < 0)
         return ctrl_error();
@@ -585,7 +586,7 @@ static int usb_host_handle_control(USBHostDevice *s, 
USBPacket *p)
 
     aurb = async_alloc();
     if (!aurb) {
-        dprintf("husb: async malloc failed\n");
+        dprintf("husb: async malloc (ctrl) failed\n");
         return USB_RET_NAK;
     }
     aurb->hdev   = s;
@@ -614,7 +615,7 @@ static int usb_host_handle_control(USBHostDevice *s, 
USBPacket *p)
     dprintf("husb: submit ctrl. len %u aurb %p\n", urb->buffer_length, aurb);
 
     if (ret < 0) {
-        dprintf("husb: submit failed. errno %d\n", errno);
+        dprintf("husb: submit ctrl failed: %s\n", strerror(errno));
         async_free(aurb);
 
         switch(errno) {
-- 
1.4.4.4