From: Daniel Thompson <daniel.thompson@linaro.org>
To: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Cc: Joe Perches <joe@perches.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-media@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-btrfs@vger.kernel.org, linux-acpi@vger.kernel.org,
netdev@vger.kernel.org, Jason Baron <jbaron@akamai.com>
Subject: Re: [PATCH v3 6/7] venus: Make debug infrastructure more flexible
Date: Thu, 11 Jun 2020 13:18:17 +0100 [thread overview]
Message-ID: <20200611121817.narzkqf5x7cvl6hp@holly.lan> (raw)
In-Reply-To: <ed7dd5b4-aace-7558-d012-fb16ce8c92d6@linaro.org>
On Thu, Jun 11, 2020 at 02:31:07PM +0300, Stanimir Varbanov wrote:
> On 6/11/20 1:52 PM, Daniel Thompson wrote:
> > On Wed, Jun 10, 2020 at 11:42:43PM -0700, Joe Perches wrote:
> >> On Thu, 2020-06-11 at 08:26 +0200, Greg Kroah-Hartman wrote:
> >>> On Wed, Jun 10, 2020 at 01:23:56PM -0700, Joe Perches wrote:
> >>>> On Wed, 2020-06-10 at 12:49 -0700, Joe Perches wrote:
> >>>>> On Wed, 2020-06-10 at 15:37 +0200, Greg Kroah-Hartman wrote:
> >>>>>> Please work with the infrastructure we have, we have spent a lot of time
> >>>>>> and effort to make it uniform to make it easier for users and
> >>>>>> developers.
> >>>>>
> >>>>> Not quite.
> >>>>>
> >>>>> This lack of debug grouping by type has been a
> >>>>> _long_ standing issue with drivers.
> >>>>>
> >>>>>> Don't regress and try to make driver-specific ways of doing
> >>>>>> things, that way lies madness...
> >>>>>
> >>>>> It's not driver specific, it allows driver developers to
> >>>>> better isolate various debug states instead of keeping
> >>>>> lists of specific debug messages and enabling them
> >>>>> individually.
> >>>>
> >>>> For instance, look at the homebrew content in
> >>>> drivers/gpu/drm/drm_print.c that does _not_ use
> >>>> dynamic_debug.
> >>>>
> >>>> MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
> >>>> "\t\tBit 0 (0x01) will enable CORE messages (drm core code)\n"
> >>>> "\t\tBit 1 (0x02) will enable DRIVER messages (drm controller code)\n"
> >>>> "\t\tBit 2 (0x04) will enable KMS messages (modesetting code)\n"
> >>>> "\t\tBit 3 (0x08) will enable PRIME messages (prime code)\n"
> >>>> "\t\tBit 4 (0x10) will enable ATOMIC messages (atomic code)\n"
> >>>> "\t\tBit 5 (0x20) will enable VBL messages (vblank code)\n"
> >>>> "\t\tBit 7 (0x80) will enable LEASE messages (leasing code)\n"
> >>>> "\t\tBit 8 (0x100) will enable DP messages (displayport code)");
> >>>> module_param_named(debug, __drm_debug, int, 0600);
> >>>>
> >>>> void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
> >>>> const char *format, ...)
> >>>> {
> >>>> struct va_format vaf;
> >>>> va_list args;
> >>>>
> >>>> if (!drm_debug_enabled(category))
> >>>> return;
> >>>
> >>> Ok, and will this proposal be able to handle stuff like this?
> >>
> >> Yes, that's the entire point.
> >
> > Currently I think there not enough "levels" to map something like
> > drm.debug to the new dyn dbg feature. I don't think it is intrinsic
> > but I couldn't find the bit of the code where the 5-bit level in struct
> > _ddebug is converted from a mask to a bit number and vice-versa.
>
> Here [1] is Joe's initial suggestion. But I decided that bitmask is a
> good start for the discussion.
>
> I guess we can add new member uint "level" in struct _ddebug so that we
> can cover more "levels" (types, groups).
I don't think it is allocating only 5 bits that is the problem!
The problem is that those 5 bits need not be encoded as a bitmask by
dyndbg, that can simply be the category code for the message. They only
need be converted into a mask when we compare them to the mask provided
by the user.
Daniel.
next prev parent reply other threads:[~2020-06-11 12:18 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-09 10:45 [PATCH v3 0/7] Venus dynamic debug Stanimir Varbanov
2020-06-09 10:45 ` [PATCH v3 1/7] Documentation: dynamic-debug: Add description of level bitmask Stanimir Varbanov
2020-06-09 11:09 ` Matthew Wilcox
2020-06-09 11:16 ` Greg Kroah-Hartman
2020-06-09 16:58 ` Joe Perches
2020-06-09 17:42 ` Edward Cree
2020-06-09 17:56 ` Joe Perches
2020-06-09 18:08 ` Edward Cree
2020-06-10 6:31 ` Greg Kroah-Hartman
2020-06-10 6:35 ` Joe Perches
2020-06-10 7:09 ` Greg Kroah-Hartman
2020-06-10 7:24 ` Joe Perches
2020-06-10 10:29 ` Stanimir Varbanov
2020-06-10 12:26 ` Greg Kroah-Hartman
2020-06-09 10:45 ` [PATCH v3 2/7] dynamic_debug: Group debug messages by " Stanimir Varbanov
2020-06-09 12:27 ` Petr Mladek
2020-06-09 10:46 ` [PATCH v3 3/7] dev_printk: Add dev_dbg_level macro over dynamic one Stanimir Varbanov
2020-06-09 10:46 ` [PATCH v3 4/7] printk: Add pr_debug_level " Stanimir Varbanov
2020-06-09 11:12 ` Greg Kroah-Hartman
2020-06-09 10:46 ` [PATCH v3 5/7] venus: Add debugfs interface to set firmware log level Stanimir Varbanov
2020-06-09 11:12 ` Greg Kroah-Hartman
2020-06-11 11:51 ` Stanimir Varbanov
2020-06-09 10:46 ` [PATCH v3 6/7] venus: Make debug infrastructure more flexible Stanimir Varbanov
2020-06-09 11:14 ` Greg Kroah-Hartman
2020-06-10 13:29 ` Stanimir Varbanov
2020-06-10 13:37 ` Greg Kroah-Hartman
2020-06-10 19:49 ` Joe Perches
2020-06-10 20:23 ` Joe Perches
2020-06-11 6:26 ` Greg Kroah-Hartman
2020-06-11 6:42 ` Joe Perches
2020-06-11 10:52 ` Daniel Thompson
2020-06-11 11:31 ` Stanimir Varbanov
2020-06-11 12:18 ` Daniel Thompson [this message]
2020-06-11 21:19 ` jim.cromie
2020-06-11 21:59 ` Jason Baron
2020-06-11 22:33 ` Joe Perches
2020-06-12 0:08 ` jim.cromie
2020-06-10 18:32 ` WIP generic module->debug_flags and dynamic_debug jim.cromie
2020-06-10 20:24 ` Joe Perches
2020-06-11 11:26 ` Rasmus Villemoes
2020-06-11 14:09 ` jim.cromie
2020-06-09 10:46 ` [PATCH v3 7/7] venus: Add a debugfs file for SSR trigger Stanimir Varbanov
2020-06-09 11:13 ` [PATCH v3 0/7] Venus dynamic debug Matthew Wilcox
2020-06-09 16:03 ` Randy Dunlap
2020-06-09 16:49 ` Joe Perches
2020-06-09 21:21 ` jim.cromie
2020-06-09 22:23 ` Joe Perches
2020-06-10 1:58 ` Joe Perches
2020-06-10 3:10 ` jim.cromie
2020-06-09 16:40 ` Joe Perches
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