[PATCH] drm/msm: Set max segment size earlier

From: Rob Clark
Date: Mon May 01 2023 - 16:50:03 EST


From: Rob Clark <robdclark@xxxxxxxxxxxx>

Fixes the following splat on a6xx gen2+ (a640, a650, a660 families),
a6xx gen1 has smaller GMU allocations so they fit under the default
64K max segment size.

------------[ cut here ]------------
DMA-API: msm_dpu ae01000.display-controller: mapping sg segment longer than device claims to support [len=126976] [max=65536]
WARNING: CPU: 5 PID: 9 at kernel/dma/debug.c:1160 debug_dma_map_sg+0x288/0x314
Modules linked in:
CPU: 5 PID: 9 Comm: kworker/u16:0 Not tainted 6.3.0-rc2-debug+ #629
Hardware name: Google Villager (rev1+) with LTE (DT)
Workqueue: events_unbound deferred_probe_work_func
pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : debug_dma_map_sg+0x288/0x314
lr : debug_dma_map_sg+0x288/0x314
sp : ffffffc00809b560
x29: ffffffc00809b560 x28: 0000000000000060 x27: 0000000000000000
x26: 0000000000010000 x25: 0000000000000004 x24: 0000000000000004
x23: ffffffffffffffff x22: ffffffdb31693cc0 x21: ffffff8080935800
x20: ffffff8087417400 x19: ffffff8087a45010 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000010000
x14: 0000000000000001 x13: ffffffffffffffff x12: ffffffffffffffff
x11: 0000000000000000 x10: 000000000000000a x9 : ffffffdb2ff05e14
x8 : ffffffdb31275000 x7 : ffffffdb2ff08908 x6 : 0000000000000000
x5 : 0000000000000001 x4 : ffffffdb2ff08a74 x3 : ffffffdb31275008
x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffffff80803a9a80
Call trace:
debug_dma_map_sg+0x288/0x314
__dma_map_sg_attrs+0x80/0xe4
dma_map_sgtable+0x30/0x4c
get_pages+0x1d4/0x1e4
msm_gem_pin_pages_locked+0xbc/0xf8
msm_gem_pin_vma_locked+0x58/0xa0
msm_gem_get_and_pin_iova_range+0x98/0xac
a6xx_gmu_memory_alloc+0x7c/0x128
a6xx_gmu_init+0x16c/0x9b0
a6xx_gpu_init+0x38c/0x3e4
adreno_bind+0x214/0x264
component_bind_all+0x128/0x1f8
msm_drm_bind+0x2b8/0x608
try_to_bring_up_aggregate_device+0x88/0x1a4
__component_add+0xec/0x13c
component_add+0x1c/0x28
dp_display_probe+0x3f8/0x43c
platform_probe+0x70/0xc4
really_probe+0x148/0x280
__driver_probe_device+0xc8/0xe0
driver_probe_device+0x44/0x100
__device_attach_driver+0x64/0xdc
bus_for_each_drv+0xb0/0xd8
__device_attach+0xd8/0x168
device_initial_probe+0x1c/0x28
bus_probe_device+0x44/0xb0
deferred_probe_work_func+0xc8/0xe0
process_one_work+0x2e0/0x488
process_scheduled_works+0x4c/0x50
worker_thread+0x218/0x274
kthread+0xf0/0x100
ret_from_fork+0x10/0x20
irq event stamp: 293712
hardirqs last enabled at (293711): [<ffffffdb2ff0893c>] vprintk_emit+0x160/0x25c
hardirqs last disabled at (293712): [<ffffffdb30b48130>] el1_dbg+0x24/0x80
softirqs last enabled at (279520): [<ffffffdb2fe10420>] __do_softirq+0x21c/0x4bc
softirqs last disabled at (279515): [<ffffffdb2fe16708>] ____do_softirq+0x18/0x24
---[ end trace 0000000000000000 ]---

Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_drv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 3a74b5653e96..6dec1a3534f2 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -440,27 +440,27 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
fs_reclaim_acquire(GFP_KERNEL);
might_lock(&priv->lru.lock);
fs_reclaim_release(GFP_KERNEL);

drm_mode_config_init(ddev);

ret = msm_init_vram(ddev);
if (ret)
goto err_drm_dev_put;

+ dma_set_max_seg_size(dev, UINT_MAX);
+
/* Bind all our sub-components: */
ret = component_bind_all(dev, ddev);
if (ret)
goto err_drm_dev_put;

- dma_set_max_seg_size(dev, UINT_MAX);
-
msm_gem_shrinker_init(ddev);

if (priv->kms_init) {
ret = priv->kms_init(ddev);
if (ret) {
DRM_DEV_ERROR(dev, "failed to load kms\n");
priv->kms = NULL;
goto err_msm_uninit;
}
kms = priv->kms;
--
2.39.2