[Intel-gfx] [PATCH] drm/i915: make prelim hw msg in log a bit more harsh

[Rob Clark]

On Fri, Sep 18, 2015 at 7:59 AM, Jani Nikula
<jani.nikula at linux.intel.com> wrote:
> On Fri, 18 Sep 2015, Rob Clark <robdclark at gmail.com> wrote:
>> Apparently some people see this message and try to turn on
>> preliminary_hw_support.  And then for some reason are surprised
>> when it doesn't work.  So let's set expectations a bit lower.
>
> I think the message goes wrong already at the beginning, "hardware
> requires preliminary hardware support". The hardware really requires
> full support, but preliminary is all we've got so far, and that's been
> disabled by default...
>
> How about something along the lines of,
>
> """
> This kernel version does not properly support the hardware.
> Preliminary support disabled by default.
> See CONFIG_DRM_I915_PRELIMINARY_HW_SUPPORT or i915.preliminary_hw_support.
> """

I'm not too picky on the wording, but I think it should include
something along the lines of "unsupported" or "use at your own risk"
just to make it clear that you may be left with a dark screen..

I kinda think we should also drop
CONFIG_DRM_I915_PRELIMINARY_HW_SUPPORT too and leave only the module
param (since the config option encourages one to build a kernel that
won't work unless you know to override i915.reliminary_hw_support in
grub.

After that, perhaps switch to module_param_named_unsafe() for good measure..

BR,
-R

> BR,
> Jani.
>
>
>
>>
>> Signed-off-by: Rob Clark <robdclark at gmail.com>
>> ---
>>  drivers/gpu/drm/i915/i915_drv.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>> index 8edcec8..5e87fe1 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -926,7 +926,8 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>>
>>       if (IS_PRELIMINARY_HW(intel_info) && !i915.preliminary_hw_support) {
>>               DRM_INFO("This hardware requires preliminary hardware support.\n"
>> -                      "See CONFIG_DRM_I915_PRELIMINARY_HW_SUPPORT, and/or modparam preliminary_hw_support\n");
>> +                      "See CONFIG_DRM_I915_PRELIMINARY_HW_SUPPORT, and/or modparam preliminary_hw_support.\n"
>> +                      "Note that preliminary hw support is unsupported, use at your own risk!\n");
>>               return -ENODEV;
>>       }
>>
>> --
>> 2.4.3
>>
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>
> --
> Jani Nikula, Intel Open Source Technology Center