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

[Thomas Zimmermann]

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},
>>  	{ 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 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
URL: <https://lists.freedesktop.org/archives/dri-devel/attachments/20191126/a0969863/attachment-0001.sig>