From 7c20d213dd3cd6295bf9162730e7a368af957854 Mon Sep 17 00:00:00 2001 From: Sinclair Yeh Date: Wed, 29 Jun 2016 11:29:47 -0700 Subject: drm/vmwgfx: Work around mode set failure in 2D VMs In a low-memory 2D VM, fbdev can take up a large percentage of available memory, making them unavailable for other DRM clients. Since we do not take fbdev into account when filtering modes, we end up claiming to support more modes than we actually do. As a result, users get a black screen when setting a mode too large for current available memory. In a low-memory VM configuration, users can get a black screen for a mode as low as 1024x768. The current mode filtering mechanism keys off of SVGA_REG_SUGGESTED_GBOBJECT_MEM_SIZE_KB, i.e. the maximum amount of surface memory we have. Since this value is a performance suggestion, not a hard limit, and since there should not be much of a performance impact for a 2D VM, rather than filtering out more modes, we will just allow ourselves to exceed the SVGA's performance suggestion. Also changed assumed bpp to 32 from 16 to make sure we can actually support all the modes listed. Signed-off-by: Sinclair Yeh Reviewed-by: Thomas Hellstrom Cc: --- drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'drivers/gpu/drm/vmwgfx/vmwgfx_kms.c') diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c index 55231cce73a0..077f16d6de6f 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c @@ -1553,14 +1553,7 @@ int vmw_du_connector_fill_modes(struct drm_connector *connector, DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_PVSYNC) }; int i; - u32 assumed_bpp = 2; - - /* - * If using screen objects, then assume 32-bpp because that's what the - * SVGA device is assuming - */ - if (dev_priv->active_display_unit == vmw_du_screen_object) - assumed_bpp = 4; + u32 assumed_bpp = 4; if (dev_priv->active_display_unit == vmw_du_screen_target) { max_width = min(max_width, dev_priv->stdu_max_width); -- cgit v1.2.3 From 04319d89fbec72dfd60738003c3813b97c1d5f5a Mon Sep 17 00:00:00 2001 From: Sinclair Yeh Date: Wed, 29 Jun 2016 12:15:48 -0700 Subject: drm/vmwgfx: Add an option to change assumed FB bpp Offer an option for advanced users who want larger modes at 16bpp. This becomes necessary after the fix: "Work around mode set failure in 2D VMs." Without this patch, there would be no way for existing advanced users to get to a high res mode, and the regression is they will likely get a black screen after a software update on their current VM. Signed-off-by: Sinclair Yeh Reviewed-by: Thomas Hellstrom Cc: --- drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 5 +++++ drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 1 + drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 3 +++ 3 files changed, 9 insertions(+) (limited to 'drivers/gpu/drm/vmwgfx/vmwgfx_kms.c') diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c index fc9ad0050d23..8d528fcf6e96 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c @@ -233,6 +233,7 @@ static int vmw_force_iommu; static int vmw_restrict_iommu; static int vmw_force_coherent; static int vmw_restrict_dma_mask; +static int vmw_assume_16bpp; static int vmw_probe(struct pci_dev *, const struct pci_device_id *); static void vmw_master_init(struct vmw_master *); @@ -249,6 +250,8 @@ MODULE_PARM_DESC(force_coherent, "Force coherent TTM pages"); module_param_named(force_coherent, vmw_force_coherent, int, 0600); MODULE_PARM_DESC(restrict_dma_mask, "Restrict DMA mask to 44 bits with IOMMU"); module_param_named(restrict_dma_mask, vmw_restrict_dma_mask, int, 0600); +MODULE_PARM_DESC(assume_16bpp, "Assume 16-bpp when filtering modes"); +module_param_named(assume_16bpp, vmw_assume_16bpp, int, 0600); static void vmw_print_capabilities(uint32_t capabilities) @@ -660,6 +663,8 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset) dev_priv->vram_start = pci_resource_start(dev->pdev, 1); dev_priv->mmio_start = pci_resource_start(dev->pdev, 2); + dev_priv->assume_16bpp = !!vmw_assume_16bpp; + dev_priv->enable_fb = enable_fbdev; vmw_write(dev_priv, SVGA_REG_ID, SVGA_ID_2); diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h index 1980e2a28265..89fb19443a3f 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h @@ -386,6 +386,7 @@ struct vmw_private { spinlock_t hw_lock; spinlock_t cap_lock; bool has_dx; + bool assume_16bpp; /* * VGA registers. diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c index 077f16d6de6f..e29da45a2847 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c @@ -1555,6 +1555,9 @@ int vmw_du_connector_fill_modes(struct drm_connector *connector, int i; u32 assumed_bpp = 4; + if (dev_priv->assume_16bpp) + assumed_bpp = 2; + if (dev_priv->active_display_unit == vmw_du_screen_target) { max_width = min(max_width, dev_priv->stdu_max_width); max_height = min(max_height, dev_priv->stdu_max_height); -- cgit v1.2.3