On Thursday, May 22, 2014 12:47:47 PM Bjørn Mork wrote:
> Commit 1a699476e258 ("ACPI / hotplug / PCI: Hotplug notifications
> from acpi_bus_notify()") added debug messages for a few common
> events. These debug messages are unconditionally enabled if
> CONFIG_DYNAMIC_DEBUG is defined, contrary to the documented
> meaning, making the ACPI system spew lots of unwanted noise on
> any kernel with dynamic debugging.
>
> The bug was introduced by commit fbfddae69657 ("ACPI: Add
> acpi_handle_<level>() interfaces"), which added the
> CONFIG_DYNAMIC_DEBUG dependency without respecting its meaning.
>
> Fix by adding real support for dynamic_debug.
>
> Fixes: fbfddae69657 ("ACPI: Add acpi_handle_<level>() interfaces")
> Signed-off-by: Bjørn Mork <bjorn@xxxxxxx>
Queued up for 3.16, thanks!
> ---
> Background: I suddenly got lots of these messages in v3.15-rcX
> without having enabled any ACPI debugging AFAIK:
>
> ACPI: \_SB_.PCI0.HDEF: ACPI_NOTIFY_DEVICE_WAKE event
> ACPI: \_SB_.PCI0.EHC1: ACPI_NOTIFY_DEVICE_WAKE event
> ACPI: \_SB_.PCI0.EHC0: ACPI_NOTIFY_DEVICE_WAKE event
> ACPI: \_SB_.PCI0.IGBE: ACPI_NOTIFY_DEVICE_WAKE event
> ACPI: \_SB_.PCI0.HDEF: ACPI_NOTIFY_DEVICE_WAKE event
>
> The reason turned out to be that I have CONFIG_DYNAMIC_DEBUG
> enabled. Which I must say I have primarily to debug other
> stuff, and *not* ACPI.
>
> An alternative way to fix this would of course be just removing
> the bogus CONFIG_DYNAMIC_DEBUG dependency. But I guess it's better
> to actually support dynamic debugging?
>
>
> Bjørn
>
>
> drivers/acpi/utils.c | 64 ++++++++++++++++++++++++++++++++++++++++----------
> include/linux/acpi.h | 22 +++++++++++++++--
> 2 files changed, 72 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
> index bba526148583..07c8c5a5ee95 100644
> --- a/drivers/acpi/utils.c
> +++ b/drivers/acpi/utils.c
> @@ -30,6 +30,7 @@
> #include <linux/types.h>
> #include <linux/hardirq.h>
> #include <linux/acpi.h>
> +#include <linux/dynamic_debug.h>
>
> #include "internal.h"
>
> @@ -457,6 +458,24 @@ acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
> EXPORT_SYMBOL(acpi_evaluate_ost);
>
> /**
> + * acpi_handle_path: Return the object path of handle
> + *
> + * Caller must free the returned buffer
> + */
> +static char *acpi_handle_path(acpi_handle handle)
> +{
> + struct acpi_buffer buffer = {
> + .length = ACPI_ALLOCATE_BUFFER,
> + .pointer = NULL
> + };
> +
> + if (in_interrupt() ||
> + acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
> + return NULL;
> + return buffer.pointer;
> +}
> +
> +/**
> * acpi_handle_printk: Print message with ACPI prefix and object path
> *
> * This function is called through acpi_handle_<level> macros and prints
> @@ -469,29 +488,50 @@ acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
> {
> struct va_format vaf;
> va_list args;
> - struct acpi_buffer buffer = {
> - .length = ACPI_ALLOCATE_BUFFER,
> - .pointer = NULL
> - };
> const char *path;
>
> va_start(args, fmt);
> vaf.fmt = fmt;
> vaf.va = &args;
>
> - if (in_interrupt() ||
> - acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
> - path = "<n/a>";
> - else
> - path = buffer.pointer;
> -
> - printk("%sACPI: %s: %pV", level, path, &vaf);
> + path = acpi_handle_path(handle);
> + printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
>
> va_end(args);
> - kfree(buffer.pointer);
> + kfree(path);
> }
> EXPORT_SYMBOL(acpi_handle_printk);
>
> +#if defined(CONFIG_DYNAMIC_DEBUG)
> +/**
> + * __acpi_handle_debug: pr_debug with ACPI prefix and object path
> + *
> + * This function is called through acpi_handle_debug macro and debug
> + * prints a message with ACPI prefix and object path. This function
> + * acquires the global namespace mutex to obtain an object path. In
> + * interrupt context, it shows the object path as <n/a>.
> + */
> +void
> +__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
> + const char *fmt, ...)
> +{
> + struct va_format vaf;
> + va_list args;
> + const char *path;
> +
> + va_start(args, fmt);
> + vaf.fmt = fmt;
> + vaf.va = &args;
> +
> + path = acpi_handle_path(handle);
> + __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
> +
> + va_end(args);
> + kfree(path);
> +}
> +EXPORT_SYMBOL(__acpi_handle_debug);
> +#endif
> +
> /**
> * acpi_has_method: Check whether @handle has a method named @name
> * @handle: ACPI device handle
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 7a8f2cd66c8b..0e2569031a6f 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -37,6 +37,7 @@
>
> #include <linux/list.h>
> #include <linux/mod_devicetable.h>
> +#include <linux/dynamic_debug.h>
>
> #include <acpi/acpi.h>
> #include <acpi/acpi_bus.h>
> @@ -589,6 +590,14 @@ static inline __printf(3, 4) void
> acpi_handle_printk(const char *level, void *handle, const char *fmt, ...) {}
> #endif /* !CONFIG_ACPI */
>
> +#if defined(CONFIG_ACPI) && defined(CONFIG_DYNAMIC_DEBUG)
> +__printf(3, 4)
> +void __acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle, const char *fmt, ...);
> +#else
> +#define __acpi_handle_debug(descriptor, handle, fmt, ...) \
> + acpi_handle_printk(KERN_DEBUG, handle, fmt, ##__VA_ARGS__);
> +#endif
> +
> /*
> * acpi_handle_<level>: Print message with ACPI prefix and object path
> *
> @@ -610,11 +619,19 @@ acpi_handle_printk(const char *level, void *handle, const char *fmt, ...) {}
> #define acpi_handle_info(handle, fmt, ...) \
> acpi_handle_printk(KERN_INFO, handle, fmt, ##__VA_ARGS__)
>
> -/* REVISIT: Support CONFIG_DYNAMIC_DEBUG when necessary */
> -#if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG)
> +#if defined(DEBUG)
> #define acpi_handle_debug(handle, fmt, ...) \
> acpi_handle_printk(KERN_DEBUG, handle, fmt, ##__VA_ARGS__)
> #else
> +#if defined(CONFIG_DYNAMIC_DEBUG)
> +#define acpi_handle_debug(handle, fmt, ...) \
> +do { \
> + DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
> + if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)) \
> + __acpi_handle_debug(&descriptor, handle, pr_fmt(fmt), \
> + ##__VA_ARGS__); \
> +} while (0)
> +#else
> #define acpi_handle_debug(handle, fmt, ...) \
> ({ \
> if (0) \
> @@ -622,5 +639,6 @@ acpi_handle_printk(const char *level, void *handle, const char *fmt, ...) {}
> 0; \
> })
> #endif
> +#endif
>
> #endif /*_LINUX_ACPI_H*/
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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