[PATCH] UHCI: improve debugging code

This patch (as626) makes some improvements to the debugging code in
uhci-hcd.  The main change is that now the code won't get compiled if
CONFIG_USB_DEBUG isn't set.  But there are other changes too, like
adding a missing .owner field and printing a debugging dump if the
controller dies.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 39 insertions, 21 deletions

diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 9865f303d3fc..4edb8330c440 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -68,12 +68,16 @@ Alan Stern"
  * debug = 3, show all TDs in URBs when dumping
  */
 #ifdef DEBUG
+#define DEBUG_CONFIGURED        1
 static int debug = 1;
-#else
-static int debug = 0;
-#endif
 module_param(debug, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(debug, "Debug level");
+
+#else
+#define DEBUG_CONFIGURED        0
+#define debug                   0
+#endif
+
 static char *errbuf;
 #define ERRBUF_LEN    (32 * 1024)
 
@@ -338,6 +342,12 @@ static irqreturn_t uhci_irq(struct usb_hcd *hcd, struct pt_regs *regs)
                                 dev_err(uhci_dev(uhci),
                                         "host controller halted, "
                                         "very bad!\n");
+                                if (debug > 1 && errbuf) {
+                                        /* Print the schedule for debugging */
+                                        uhci_sprint_schedule(uhci,
+                                                        errbuf, ERRBUF_LEN);
+                                        lprintk(errbuf);
+                                }
                                 hc_died(uhci);
 
                                 /* Force a callback in case there are
@@ -376,6 +386,14 @@ static void release_uhci(struct uhci_hcd *uhci)
 {
         int i;
 
+        if (DEBUG_CONFIGURED) {
+                spin_lock_irq(&uhci->lock);
+                uhci->is_initialized = 0;
+                spin_unlock_irq(&uhci->lock);
+
+                debugfs_remove(uhci->dentry);
+        }
+
         for (i = 0; i < UHCI_NUM_SKELQH; i++)
                 uhci_free_qh(uhci, uhci->skelqh[i]);
 
@@ -390,8 +408,6 @@ static void release_uhci(struct uhci_hcd *uhci)
         dma_free_coherent(uhci_dev(uhci),
                         UHCI_NUMFRAMES * sizeof(*uhci->frame),
                         uhci->frame, uhci->frame_dma_handle);
-
-        debugfs_remove(uhci->dentry);
 }
 
 static int uhci_reset(struct usb_hcd *hcd)
@@ -474,17 +490,6 @@ static int uhci_start(struct usb_hcd *hcd)
 
         hcd->uses_new_polling = 1;
 
-        dentry = debugfs_create_file(hcd->self.bus_name,
-                        S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root, uhci,
-                        &uhci_debug_operations);
-        if (!dentry) {
-                dev_err(uhci_dev(uhci),
-                                "couldn't create uhci debugfs entry\n");
-                retval = -ENOMEM;
-                goto err_create_debug_entry;
-        }
-        uhci->dentry = dentry;
-
         uhci->fsbr = 0;
         uhci->fsbrtimeout = 0;
 
@@ -495,6 +500,19 @@ static int uhci_start(struct usb_hcd *hcd)
 
         init_waitqueue_head(&uhci->waitqh);
 
+        if (DEBUG_CONFIGURED) {
+                dentry = debugfs_create_file(hcd->self.bus_name,
+                                S_IFREG|S_IRUGO|S_IWUSR, uhci_debugfs_root,
+                                uhci, &uhci_debug_operations);
+                if (!dentry) {
+                        dev_err(uhci_dev(uhci), "couldn't create uhci "
+                                        "debugfs entry\n");
+                        retval = -ENOMEM;
+                        goto err_create_debug_entry;
+                }
+                uhci->dentry = dentry;
+        }
+
         uhci->frame = dma_alloc_coherent(uhci_dev(uhci),
                         UHCI_NUMFRAMES * sizeof(*uhci->frame),
                         &uhci->frame_dma_handle, 0);
@@ -609,6 +627,7 @@ static int uhci_start(struct usb_hcd *hcd)
         mb();
 
         configure_hc(uhci);
+        uhci->is_initialized = 1;
         start_rh(uhci);
         return 0;
 
@@ -872,16 +891,15 @@ static int __init uhci_hcd_init(void)
         if (usb_disabled())
                 return -ENODEV;
 
-        if (debug) {
+        if (DEBUG_CONFIGURED) {
                 errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
                 if (!errbuf)
                         goto errbuf_failed;
+                uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
+                if (!uhci_debugfs_root)
+                        goto debug_failed;
         }
 
-        uhci_debugfs_root = debugfs_create_dir("uhci", NULL);
-        if (!uhci_debugfs_root)
-                goto debug_failed;
-
         uhci_up_cachep = kmem_cache_create("uhci_urb_priv",
                 sizeof(struct urb_priv), 0, 0, NULL, NULL);
         if (!uhci_up_cachep)