[PATCH v2 3/4] dm: core: migrate debug() messages to use dm_warn

[Sean Anderson]

On 10/2/24 05:25, Quentin Schulz wrote:
> Hi Alexander,
> 
> On 10/2/24 10:37 AM, Alexander Dahl wrote:
>> Hello Quentin,
>>
>> sorry for being late to the party, but I just tested v2024.10-rc6 and
>> my console output looks like this now:
>>
>>      ofnode_read_bool: bootph-all: true
>>      ofnode_read_u32_array: ranges: ofnode_read_bool: bootph-all: false
>>      ofnode_read_bool: bootph-some-ram: false
>>      ofnode_read_bool: bootph-pre-ram: false
>>      ofnode_read_bool: bootph-pre-sram: false
>>      ofnode_read_bool: u-boot,dm-pre-reloc: false
>>      ofnode_read_bool: u-boot,dm-pre-proper: false
>>      ofnode_read_bool: u-boot,dm-spl: false
>>      ofnode_read_bool: u-boot,dm-tpl: false
>>      ofnode_read_bool: u-boot,dm-vpl: false
>>      ofnode_read_bool: bootph-all: false
>>      ofnode_read_bool: bootph-some-ram: false
>>      ofnode_read_bool: bootph-pre-ram: false
>>      ofnode_read_bool: bootph-pre-sram: false
>>      ofnode_read_bool: u-boot,dm-pre-reloc: false
>>      ofnode_read_bool: u-boot,dm-pre-proper: false
>>      ofnode_read_bool: u-boot,dm-spl: false
>>      ofnode_read_bool: u-boot,dm-tpl: false
>>      ofnode_read_bool: u-boot,dm-vpl: false
>>      ofnode_read_bool: bootph-all: true
>>      ofnode_read_u32_array: ranges: ofnode_read_bool: bootph-all: true
>>      ofnode_read_u32_array: ranges: ofnode_read_bool: bootph-all: true
>>      ofnode_read_bool: bootph-all: true
>>      ofnode_read_bool: bootph-all: false
>>      …
>>
>> This goes on for several screen pages, and clutters the usual output.
>> I first thought I messed up CONFIG_LOGLEVEL or CONFIG_LOG, but no.
>> All I had done was setting CONFIG_DM_WARN …
>>
>> Am Tue, Jun 11, 2024 at 03:04:26PM +0200 schrieb Quentin Schulz:
>>> From: Quentin Schulz <quentin.schulz at cherry.de>
>>>
>>> Prior to that, seeing the debug() messages required to enable DM_DEBUG
>>> which defines DEBUG (and then _DEBUG) which in turn makes failing
>>> assert() calls reset U-Boot which isn't necessarily what is desired.
>>>
>>> Instead, let's migrate to dm_warn which is using log_debug when unset or
>>> log_warn when set.
>>>
>>> While at it, reword the DM_DEBUG symbol in Kconfig to explain what it
>>> now actually does.
>>
>> CONFIG_DM_WARN currently reads like this:
>>
>>      Enable this to see warnings related to driver model.
>>
>>      Warnings may help with debugging, such as when expected devices do
>>      not bind correctly. If the option is disabled, dm_warn() is compiled
>>      out - it will do nothing when called.
>>
>> Instead of just useful warnings, users get debug messages all over the
>> place now.  Is this actually intended behaviour?  Can this be fixed
>> before v2024.10 release please?
>>
> 
> There are basically less than 3 working days left before v2024.10 is released and I'm inclined to say this is annoying rather than a bug, so I am not entirely sure this will 1) make it in time if we agree on a fix (needs to include review process in those 3 working days) 2) be acceptable for a late addition in the release cycle. Let's try though, maybe we can figure something out.

This is a bug. Printing this many messages will have a major impact on boot times.

A config going from "may print out a few more lines of extra info" to "firehose"
is very surprising to users (as evidenced by Alexander's email).

If you can't figure out which lines to disable, I recommend simply reverting the
patch.

--Sean