On Wed, 13 Apr 2016, Rafał Miłecki wrote:
> Hi,
>
> I'm trying to debug some EHCI issue so I enabled debugging by adding
> ccflags-y := -DDEBUG
> to the drivers/usb/host/Makefile
>
> Some of debugging lines contain random memory, e.g.:
> ehci-platform ehci-platform.0: .|��`|���5P5@�3�.��*�.|��o
>
> It's caused by dbg_status, dbg_cmd and dbg_port calling ehci_dbg even with:
> # CONFIG_DYNAMIC_DEBUG
>
> The lack of above config implies using dummy dbg_status_buf,
> dbg_command_buf and dbg_port_buf. They don't print anything to the
> buffer and it stays uninitialized.
>
> Can you give me a hint how to solve this (apart from enabling
> CONFIG_DYNAMIC_DEBUG for my debugging which I did)? Should dbg_*_buf
> functions return some error instead of 0? We could check for that in
> dbg_* functions then. Unfortunately I'm not sure how it's going to
> affect other places, e.g. fill_registers_buffer.
That's a real problem. The whole ehci-dbg.c file needs to be cleaned
up -- we should just remove all the debugging when CONFIG_DYNAMIC_DEBUG
isn't enabled.
See if the patch below fixes the problem.
Alan Stern
Index: usb-4.4/drivers/usb/host/ehci-dbg.c
===================================================================
--- usb-4.4.orig/drivers/usb/host/ehci-dbg.c
+++ usb-4.4/drivers/usb/host/ehci-dbg.c
@@ -56,13 +56,6 @@ static void dbg_hcs_params (struct ehci_
label, buf);
}
}
-#else
-
-static inline void dbg_hcs_params (struct ehci_hcd *ehci, char *label) {}
-
-#endif
-
-#ifdef CONFIG_DYNAMIC_DEBUG
/* check the values in the HCCPARAMS register
* (host controller _Capability_ parameters)
@@ -95,13 +88,6 @@ static void dbg_hcc_params (struct ehci_
" 32 periodic list" : "");
}
}
-#else
-
-static inline void dbg_hcc_params (struct ehci_hcd *ehci, char *label) {}
-
-#endif
-
-#ifdef CONFIG_DYNAMIC_DEBUG
static void __maybe_unused
dbg_qtd (const char *label, struct ehci_hcd *ehci, struct ehci_qtd *qtd)
@@ -280,29 +266,6 @@ dbg_port_buf (char *buf, unsigned len, c
(status & PORT_CONNECT) ? " CONNECT" : "");
}
-#else
-static inline void __maybe_unused
-dbg_qh (char *label, struct ehci_hcd *ehci, struct ehci_qh *qh)
-{}
-
-static inline int __maybe_unused
-dbg_status_buf (char *buf, unsigned len, const char *label, u32 status)
-{ return 0; }
-
-static inline int __maybe_unused
-dbg_command_buf (char *buf, unsigned len, const char *label, u32 command)
-{ return 0; }
-
-static inline int __maybe_unused
-dbg_intr_buf (char *buf, unsigned len, const char *label, u32 enable)
-{ return 0; }
-
-static inline int __maybe_unused
-dbg_port_buf (char *buf, unsigned len, const char *label, int port, u32 status)
-{ return 0; }
-
-#endif /* CONFIG_DYNAMIC_DEBUG */
-
/* functions have the "wrong" filename when they're output... */
#define dbg_status(ehci, label, status) { \
char _buf [80]; \
@@ -324,13 +287,6 @@ dbg_port_buf (char *buf, unsigned len, c
/*-------------------------------------------------------------------------*/
-#ifdef STUB_DEBUG_FILES
-
-static inline void create_debug_files (struct ehci_hcd *bus) { }
-static inline void remove_debug_files (struct ehci_hcd *bus) { }
-
-#else
-
/* troubleshooting help: expose state in debugfs */
static int debug_async_open(struct inode *, struct file *);
@@ -1089,4 +1045,38 @@ static inline void remove_debug_files (s
debugfs_remove_recursive(ehci->debug_dir);
}
-#endif /* STUB_DEBUG_FILES */
+#else /* CONFIG_DYNAMIC_DEBUG */
+
+static inline void dbg_hcs_params(struct ehci_hcd *ehci, char *label) { }
+static inline void dbg_hcc_params(struct ehci_hcd *ehci, char *label) { }
+
+static inline void __maybe_unused dbg_qh(const char *label,
+ struct ehci_hcd *ehci, struct ehci_qh *qh) { }
+
+static inline int __maybe_unused dbg_status_buf(const char *buf,
+ unsigned len, const char *label, u32 status)
+{ return 0; }
+
+static inline int __maybe_unused dbg_command_buf(const char *buf,
+ unsigned len, const char *label, u32 command)
+{ return 0; }
+
+static inline int __maybe_unused dbg_intr_buf(const char *buf,
+ unsigned len, const char *label, u32 enable)
+{ return 0; }
+
+static inline int __maybe_unused dbg_port_buf(char *buf,
+ unsigned len, const char *label, int port, u32 status)
+{ return 0; }
+
+static inline void dbg_status(struct ehci_hcd *ehci, const char *label,
+ u32 status) { }
+static inline void dbg_cmd(struct ehci_hcd *ehci, const char *label,
+ u32 command) { }
+static inline void dbg_port(struct ehci_hcd *ehci, const char *label,
+ int port, u32 status) { }
+
+static inline void create_debug_files(struct ehci_hcd *bus) { }
+static inline void remove_debug_files(struct ehci_hcd *bus) { }
+
+#endif /* CONFIG_DYNAMIC_DEBUG */
Index: usb-4.4/drivers/usb/host/ehci.h
===================================================================
--- usb-4.4.orig/drivers/usb/host/ehci.h
+++ usb-4.4/drivers/usb/host/ehci.h
@@ -869,11 +869,6 @@ static inline u32 hc32_to_cpup (const st
#define ehci_warn(ehci, fmt, args...) \
dev_warn(ehci_to_hcd(ehci)->self.controller , fmt , ## args)
-
-#ifndef CONFIG_DYNAMIC_DEBUG
-#define STUB_DEBUG_FILES
-#endif
-
/*-------------------------------------------------------------------------*/
/* Declarations of things exported for use by ehci platform drivers */
--
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