Subject: Re: [PATCH] drm/stm: remove conflicting framebuffers
To:     Thomas Zimmermann <tzimmermann@suse.de>,
        Philippe Cornu <philippe.cornu@foss.st.com>,
        Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        <dri-devel@lists.freedesktop.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
References: <20211203085512.11127-1-yannick.fertre@foss.st.com>
 <7469e918-b2bf-00a9-1bbc-2f3514ec0816@suse.de>
From:   yannick Fertre <yannick.fertre@foss.st.com>
Message-ID: <169ba08b-fdaa-866e-91bf-7a353c1d713d@foss.st.com>
Date:   Mon, 6 Dec 2021 14:42:49 +0100
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Hi Thomas,


On 12/3/21 10:35 AM, Thomas Zimmermann wrote:
> Hi
> 
> Am 03.12.21 um 09:55 schrieb Yannick Fertre:
>> In case of using simplefb or another conflicting framebuffer,
>> call drm_aperture_remove_framebuffers() to remove memory allocated.
>>
>> Signed-off-by: Yannick Fertre <yannick.fertre@foss.st.com>
>> ---
>>   drivers/gpu/drm/stm/drv.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
>> index 222869b232ae..5ba46f70f081 100644
>> --- a/drivers/gpu/drm/stm/drv.c
>> +++ b/drivers/gpu/drm/stm/drv.c
>> @@ -14,6 +14,7 @@
>>   #include <linux/of_platform.h>
>>   #include <linux/pm_runtime.h>
>> +#include <drm/drm_aperture.h>
>>   #include <drm/drm_atomic.h>
>>   #include <drm/drm_atomic_helper.h>
>>   #include <drm/drm_drv.h>
>> @@ -193,6 +194,10 @@ static int stm_drm_platform_probe(struct 
>> platform_device *pdev)
>>       if (ret)
>>           goto err_put;
>> +    ret = drm_aperture_remove_framebuffers(false, &drv_driver);
>> +    if (ret)
>> +        goto err_put;
>> +
> 
> This has to be done at the very top of the probe function, before 
> anything that touches the device. Otherwise both drivers interfere with 
> each other while probing and setup's going on.
> 
> Best regards
> Thomas
> 
>>       ret = drm_dev_register(ddev, 0);
>>       if (ret)
>>           goto err_put;
>>
> 
Thanks for reviewing the patch.
I will follow your advice and push a new patch.

Yannick