From: Harry Wentland <hwentlan@amd.com>
To: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>,
amd-gfx@lists.freedesktop.org
Cc: Leo Li <sunpeng.li@amd.com>,
Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>,
Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
Harry Wentland <harry.wentland@amd.com>
Subject: Re: [PATCH] drm/amd/display: Make BREAK_TO_DEBUGGER() a debug print
Date: Fri, 22 May 2020 14:22:16 -0400 [thread overview]
Message-ID: <35b4b165-5af0-55d9-1418-b6d5fb884714@amd.com> (raw)
In-Reply-To: <20200522180326.5325-1-nicholas.kazlauskas@amd.com>
On 2020-05-22 2:03 p.m., Nicholas Kazlauskas wrote:
> [Why]
> Warnings in the kernel are generally treated as errors.
>
> The BREAK_TO_DEBUGGER macro is not a critical error or warning, but
> rather intended for developer use to help investigate behavior and
> sequences for other issues.
>
> We do still make use of DC_ERROR/ASSERT(0) in various places in the
> code for things that are genuine issues.
>
> Since most developers don't actually KGDB while debugging the kernel
> these essentially would have no value on their own since the KGDB
> breakpoint wouldn't trigger - ASSERT(0) was used as a shortcut to get
> a stacktrace.
>
> [How]
> Turn it into a DRM_DEBUG_DRIVER print instead. We unfortunately lose
> the stacktrace, but we still do retain some of the useful debug
> information this offers by having at least the function and line
> number loggable.
>
> If KGDB is supported in the kernel this will still trigger a real
> breakpoint as well.
>
> Cc: Harry Wentland <harry.wentland@amd.com>
> Cc: Leo Li <sunpeng.li@amd.com>
> Cc: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
> Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
> Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Harry
> ---
> drivers/gpu/drm/amd/display/dc/os_types.h | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/os_types.h b/drivers/gpu/drm/amd/display/dc/os_types.h
> index 6d7bca562eec..604ceb6c0375 100644
> --- a/drivers/gpu/drm/amd/display/dc/os_types.h
> +++ b/drivers/gpu/drm/amd/display/dc/os_types.h
> @@ -111,7 +111,15 @@
> #define ASSERT(expr) WARN_ON_ONCE(!(expr))
> #endif
>
> -#define BREAK_TO_DEBUGGER() ASSERT(0)
> +#if defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB)
> +#define BREAK_TO_DEBUGGER() \
> + do { \
> + DRM_DEBUG_DRIVER("%s():%d\n", __func__, __LINE__); \
> + kgdb_breakpoint(); \
> + } while (0)
> +#else
> +#define BREAK_TO_DEBUGGER() DRM_DEBUG_DRIVER("%s():%d\n", __func__, __LINE__)
> +#endif
>
> #define DC_ERR(...) do { \
> dm_error(__VA_ARGS__); \
>
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
next prev parent reply other threads:[~2020-05-22 18:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-22 18:03 [PATCH] drm/amd/display: Make BREAK_TO_DEBUGGER() a debug print Nicholas Kazlauskas
2020-05-22 18:22 ` Harry Wentland [this message]
2020-05-25 9:13 ` Michel Dänzer
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=35b4b165-5af0-55d9-1418-b6d5fb884714@amd.com \
--to=hwentlan@amd.com \
--cc=Bhawanpreet.Lakha@amd.com \
--cc=Rodrigo.Siqueira@amd.com \
--cc=amd-gfx@lists.freedesktop.org \
--cc=harry.wentland@amd.com \
--cc=nicholas.kazlauskas@amd.com \
--cc=sunpeng.li@amd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).