[Qemu-devel] [PATCH] usb: better speed mismatch error reporting

[Gerd Hoffmann <kraxel@redhat.com>]

Report the supported speeds for device and port in the error message.
Also add the speeds to the tracepoint.  And while being at it drop
the redundant error message in usb_desc_attach, usb_device_attach will
report the error anyway.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/bus.c  |   36 ++++++++++++++++++++++++++++++++----
 hw/usb/desc.c |    2 --
 trace-events  |    2 +-
 3 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/hw/usb/bus.c b/hw/usb/bus.c
index b10c290..d1827be 100644
--- a/hw/usb/bus.c
+++ b/hw/usb/bus.c
@@ -417,19 +417,47 @@ void usb_release_port(USBDevice *dev)
     bus->nfree++;
 }
 
+static void usb_mask_to_str(char *dest, size_t size,
+                            unsigned int speedmask)
+{
+    static const struct {
+        unsigned int mask;
+        const char *name;
+    } speeds[] = {
+        { .mask = USB_SPEED_MASK_FULL,  .name = "full"  },
+        { .mask = USB_SPEED_MASK_HIGH,  .name = "high"  },
+        { .mask = USB_SPEED_MASK_SUPER, .name = "super" },
+    };
+    int i, pos = 0;
+
+    for (i = 0; i < ARRAY_SIZE(speeds); i++) {
+        if (speeds[i].mask & speedmask) {
+            pos += snprintf(dest + pos, size - pos, "%s%s",
+                            pos ? "+" : "",
+                            speeds[i].name);
+        }
+    }
+}
+
 int usb_device_attach(USBDevice *dev)
 {
     USBBus *bus = usb_bus_from_device(dev);
     USBPort *port = dev->port;
+    char devspeed[32], portspeed[32];
 
     assert(port != NULL);
     assert(!dev->attached);
-    trace_usb_port_attach(bus->busnr, port->path);
+    usb_mask_to_str(devspeed, sizeof(devspeed), dev->speedmask);
+    usb_mask_to_str(portspeed, sizeof(portspeed), port->speedmask);
+    trace_usb_port_attach(bus->busnr, port->path,
+                          devspeed, portspeed);
 
     if (!(port->speedmask & dev->speedmask)) {
-        error_report("Warning: speed mismatch trying to attach "
-                     "usb device %s to bus %s",
-                     dev->product_desc, bus->qbus.name);
+        error_report("Warning: speed mismatch trying to attach"
+                     " usb device \"%s\" (%s speed)"
+                     " to bus \"%s\", port \"%s\" (%s speed)",
+                     dev->product_desc, devspeed,
+                     bus->qbus.name, port->path, portspeed);
         return -1;
     }
 
diff --git a/hw/usb/desc.c b/hw/usb/desc.c
index b389381..fce303e 100644
--- a/hw/usb/desc.c
+++ b/hw/usb/desc.c
@@ -522,8 +522,6 @@ void usb_desc_attach(USBDevice *dev)
     } else if (desc->full && (dev->port->speedmask & USB_SPEED_MASK_FULL)) {
         dev->speed = USB_SPEED_FULL;
     } else {
-        fprintf(stderr, "usb: port/device speed mismatch for \"%s\"\n",
-                usb_device_get_product_desc(dev));
         return;
     }
     usb_desc_setdefaults(dev);
diff --git a/trace-events b/trace-events
index b17cc11..b1b9c1d 100644
--- a/trace-events
+++ b/trace-events
@@ -277,7 +277,7 @@ usb_packet_state_fault(int bus, const char *port, int ep, void *p, const char *o
 
 # hw/usb/bus.c
 usb_port_claim(int bus, const char *port) "bus %d, port %s"
-usb_port_attach(int bus, const char *port) "bus %d, port %s"
+usb_port_attach(int bus, const char *port, const char *devspeed, const char *portspeed) "bus %d, port %s, devspeed %s, portspeed %s"
 usb_port_detach(int bus, const char *port) "bus %d, port %s"
 usb_port_release(int bus, const char *port) "bus %d, port %s"
 
-- 
1.7.9.7