Re: [RESEND PATCH v2] drm/vmwgfx: fix a warning due to missing dma_parms

From: Thomas Hellstrom
Date: Tue Jun 04 2019 - 06:33:49 EST


Reviewed-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>

I'll just need to give this some more testing before queueing it on
vmwgfx-fixes.

Thanks,
Thomas


On Mon, 2019-06-03 at 16:44 -0400, Qian Cai wrote:
> Booting up with DMA_API_DEBUG_SG=y generates a warning due to the
> driver
> forgot to set dma_parms appropriately. Set it just after
> vmw_dma_masks()
> in vmw_driver_load().
>
> DMA-API: vmwgfx 0000:00:0f.0: mapping sg segment longer than device
> claims to support [len=2097152] [max=65536]
> WARNING: CPU: 2 PID: 261 at kernel/dma/debug.c:1232
> debug_dma_map_sg+0x360/0x480
> Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop
> Reference Platform, BIOS 6.00 04/13/2018
> RIP: 0010:debug_dma_map_sg+0x360/0x480
> Call Trace:
> vmw_ttm_map_dma+0x3b1/0x5b0 [vmwgfx]
> vmw_bo_map_dma+0x25/0x30 [vmwgfx]
> vmw_otables_setup+0x2a8/0x750 [vmwgfx]
> vmw_request_device_late+0x78/0xc0 [vmwgfx]
> vmw_request_device+0xee/0x4e0 [vmwgfx]
> vmw_driver_load.cold+0x757/0xd84 [vmwgfx]
> drm_dev_register+0x1ff/0x340 [drm]
> drm_get_pci_dev+0x110/0x290 [drm]
> vmw_probe+0x15/0x20 [vmwgfx]
> local_pci_probe+0x7a/0xc0
> pci_device_probe+0x1b9/0x290
> really_probe+0x1b5/0x630
> driver_probe_device+0xa3/0x1a0
> device_driver_attach+0x94/0xa0
> __driver_attach+0xdd/0x1c0
> bus_for_each_dev+0xfe/0x150
> driver_attach+0x2d/0x40
> bus_add_driver+0x290/0x350
> driver_register+0xdc/0x1d0
> __pci_register_driver+0xda/0xf0
> vmwgfx_init+0x34/0x1000 [vmwgfx]
> do_one_initcall+0xe5/0x40a
> do_init_module+0x10f/0x3a0
> load_module+0x16a5/0x1a40
> __se_sys_finit_module+0x183/0x1c0
> __x64_sys_finit_module+0x43/0x50
> do_syscall_64+0xc8/0x606
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> Fixes: fb1d9738ca05 ("drm/vmwgfx: Add DRM driver for VMware Virtual
> GPU")
> Suggested-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
> Signed-off-by: Qian Cai <cai@xxxxxx>
> ---
> drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> index 4ff11a0077e1..5f690429eb89 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
> @@ -747,6 +747,8 @@ static int vmw_driver_load(struct drm_device
> *dev, unsigned long chipset)
> if (unlikely(ret != 0))
> goto out_err0;
>
> + dma_set_max_seg_size(dev->dev, U32_MAX);
> +
> if (dev_priv->capabilities & SVGA_CAP_GMR2) {
> DRM_INFO("Max GMR ids is %u\n",
> (unsigned)dev_priv->max_gmr_ids);