[PATCH 3/4] drm/mgag200: Add workaround for HW that does not support 'startadd'

Wed Dec 4 07:30:42 UTC 2019

Hi John

Am 03.12.19 um 18:55 schrieb John Donnelly:
> Hi ,
> 
> See below ,
> 
> 
>> On Nov 26, 2019, at 3:50 AM, Thomas Zimmermann <tzimmermann at suse.de> wrote:
>>
>> Hi
>>
>> Am 26.11.19 um 10:37 schrieb Daniel Vetter:
>>> On Tue, Nov 26, 2019 at 08:25:44AM +0100, Thomas Zimmermann wrote:
>>>> There's at least one system that does not interpret the value of
>>>> the device's 'startadd' field correctly, which leads to incorrectly
>>>> displayed scanout buffers. Always placing the active scanout buffer
>>>> at offset 0 works around the problem.
>>>>
>>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>>>> Reported-by: John Donnelly <john.p.donnelly at oracle.com>
>>>> Link: https://gitlab.freedesktop.org/drm/misc/issues/7
>>>
>>> Tested-by: John Donnelly <john.p.donnelly at oracle.com>
>>>
>>> (Not quite this patch, but pretty much the logic, so counts).
>>>
>>> Fixes: 81da87f63a1e ("drm: Replace drm_gem_vram_push_to_system() with kunmap + unpin")
>>> Cc: <stable at vger.kernel.org> # v5.3+
>>>
>>> Also you need the stable line on both prep patches too. For next time
>>> around,
>>>
>>> $ dim fixes 81da87f63a1e
>>>
>>> will generate all the stuff you need, including a good set of suggested
>>> Cc: you should have.
>>>
>>> On the first 3 patches, with all that stuff added:
>>>
>>> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>>
>> Thanks for the review.
>>
>> Sorry for leaving out some of the tags. I wanted to wait for feedback
>> before adding tested-by, fixes, stable. I'll split off patch 4 from the
>> series and get 1 to 3 merged ASAP.
>>
>> Best regards
>> Thomas
>>
>>>
>>> Please push these to drm-misc-next-fixes so they get backported as quickly
>>> as possible.
>>> -Daniel
>>>
>>>> ---
>>>> drivers/gpu/drm/mgag200/mgag200_drv.c | 36 ++++++++++++++++++++++++++-
>>>> drivers/gpu/drm/mgag200/mgag200_drv.h |  3 +++
>>>> 2 files changed, 38 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c
>>>> index 397f8b0a9af8..d43951caeea0 100644
>>>> --- a/drivers/gpu/drm/mgag200/mgag200_drv.c
>>>> +++ b/drivers/gpu/drm/mgag200/mgag200_drv.c
>>>> @@ -30,6 +30,8 @@ module_param_named(modeset, mgag200_modeset, int, 0400);
>>>> static struct drm_driver driver;
>>>>
>>>> static const struct pci_device_id pciidlist[] = {
>>>> +	{ PCI_VENDOR_ID_MATROX, 0x522, PCI_VENDOR_ID_SUN, 0x4852, 0, 0,
>>>> +		G200_SE_A | MGAG200_FLAG_HW_BUG_NO_STARTADD},
> 
> 
> 
> I will have an additional list of vendor IDs (0x4852)  I will provide in a follow up patch shortly .  This fixes only 1 flavor  of server.

Thank you for all the testing you do. We can add these ids as necessary.

Before, I posted a patch at [1] that prints an internal unique id. The
id of your original test machine was 0x2 IIRC.

My guess is that the problem might be related to the chip's revision. If
you have the option of booting your own kernels on all these machines,
could you apply the patch and look for a pattern in these ids? Maybe
only revision 0x2 is affected.

Best regards
Thomas

[1]
https://gitlab.freedesktop.org/drm/misc/uploads/1d5d9a75571c2bac71f80e0d2411e840/0001-drm-mgag200-Print-unique-revision-id-for-G200SE.patch

> 
> 
> Thank you .
> 
> 
> 
> 
> 
> 
>>>> 	{ PCI_VENDOR_ID_MATROX, 0x522, PCI_ANY_ID, PCI_ANY_ID, 0, 0, G200_SE_A },
>>>> 	{ PCI_VENDOR_ID_MATROX, 0x524, PCI_ANY_ID, PCI_ANY_ID, 0, 0, G200_SE_B },
>>>> 	{ PCI_VENDOR_ID_MATROX, 0x530, PCI_ANY_ID, PCI_ANY_ID, 0, 0, G200_EV },
>>>> @@ -60,6 +62,35 @@ static void mga_pci_remove(struct pci_dev *pdev)
>>>>
>>>> DEFINE_DRM_GEM_FOPS(mgag200_driver_fops);
>>>>
>>>> +static bool mgag200_pin_bo_at_0(const struct mga_device *mdev)
>>>> +{
>>>> +	return mdev->flags & MGAG200_FLAG_HW_BUG_NO_STARTADD;
>>>> +}
>>>> +
>>>> +int mgag200_driver_dumb_create(struct drm_file *file,
>>>> +			       struct drm_device *dev,
>>>> +			       struct drm_mode_create_dumb *args)
>>>> +{
>>>> +	struct mga_device *mdev = dev->dev_private;
>>>> +	unsigned long pg_align;
>>>> +
>>>> +	if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
>>>> +		return -EINVAL;
>>>> +
>>>> +	pg_align = 0ul;
>>>> +
>>>> +	/*
>>>> +	 * Aligning scanout buffers to the size of the video ram forces
>>>> +	 * placement at offset 0. Works around a bug where HW does not
>>>> +	 * respect 'startadd' field.
>>>> +	 */
>>>> +	if (mgag200_pin_bo_at_0(mdev))
>>>> +		pg_align = PFN_UP(mdev->mc.vram_size);
>>>> +
>>>> +	return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev,
>>>> +					     pg_align, false, args);
>>>> +}
>>>> +
>>>> static struct drm_driver driver = {
>>>> 	.driver_features = DRIVER_GEM | DRIVER_MODESET,
>>>> 	.load = mgag200_driver_load,
>>>> @@ -71,7 +102,10 @@ static struct drm_driver driver = {
>>>> 	.major = DRIVER_MAJOR,
>>>> 	.minor = DRIVER_MINOR,
>>>> 	.patchlevel = DRIVER_PATCHLEVEL,
>>>> -	DRM_GEM_VRAM_DRIVER
>>>> +	.debugfs_init = drm_vram_mm_debugfs_init,
>>>> +	.dumb_create = mgag200_driver_dumb_create,
>>>> +	.dumb_map_offset = drm_gem_vram_driver_dumb_mmap_offset,
>>>> +	.gem_prime_mmap = drm_gem_prime_mmap,
>>>> };
>>>>
>>>> static struct pci_driver mgag200_pci_driver = {
>>>> diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h
>>>> index 4b4f9ce74a84..aa32aad222c2 100644
>>>> --- a/drivers/gpu/drm/mgag200/mgag200_drv.h
>>>> +++ b/drivers/gpu/drm/mgag200/mgag200_drv.h
>>>> @@ -150,6 +150,9 @@ enum mga_type {
>>>> 	G200_EW3,
>>>> };
>>>>
>>>> +/* HW does not handle 'startadd' field correct. */
>>>> +#define MGAG200_FLAG_HW_BUG_NO_STARTADD	(1ul << 8)
>>>> +
>>>> #define MGAG200_TYPE_MASK	(0x000000ff)
>>>> #define MGAG200_FLAG_MASK	(0x00ffff00)
>>>>
>>>> -- 
>>>> 2.23.0
>>>>
>>>
>>
>> -- 
>> Thomas Zimmermann
>> Graphics Driver Developer
>> SUSE Software Solutions Germany GmbH
>> Maxfeldstr. 5, 90409 NÃ¼rnberg, Germany
>> (HRB 36809, AG NÃ¼rnberg)
>> GeschÃ¤ftsfÃ¼hrer: Felix ImendÃ¶rffer
>>
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 NÃ¼rnberg, Germany
(HRB 36809, AG NÃ¼rnberg)
GeschÃ¤ftsfÃ¼hrer: Felix ImendÃ¶rffer

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