On Fri, Oct 22, 2021 at 12:15 PM Jessica Zhang jesszhan@codeaurora.org wrote:
On 10/22/2021 10:20 AM, Rob Clark wrote:
From: Rob Clark robdclark@chromium.org
We know the upper bound on # of mixers (ie. two), so lets just allocate this on the stack.
Fixes:
BUG: sleeping function called from invalid context at include/linux/sched/mm.h:201 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/0 INFO: lockdep is turned off. irq event stamp: 43642 hardirqs last enabled at (43641): [<ffffffe24dd276bc>] cpuidle_enter_state+0x158/0x25c hardirqs last disabled at (43642): [<ffffffe24dfff450>] enter_el1_irq_or_nmi+0x10/0x1c softirqs last enabled at (43620): [<ffffffe24d4103fc>] __do_softirq+0x1e4/0x464 softirqs last disabled at (43615): [<ffffffe24d48bd90>] __irq_exit_rcu+0x104/0x150 CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 5.15.0-rc3-debug+ #105 Hardware name: Google Lazor (rev1 - 2) with LTE (DT) Call trace: dump_backtrace+0x0/0x18c show_stack+0x24/0x30 dump_stack_lvl+0xa0/0xd4 dump_stack+0x18/0x34 ___might_sleep+0x1e0/0x1f0 __might_sleep+0x78/0x8c slab_pre_alloc_hook.constprop.0+0x48/0x6c __kmalloc+0xc8/0x21c dpu_crtc_vblank_callback+0x158/0x1f8 dpu_encoder_vblank_callback+0x70/0xc4 dpu_encoder_phys_vid_vblank_irq+0x50/0x12c dpu_core_irq+0x1bc/0x1d0 dpu_irq+0x1c/0x28 msm_irq+0x34/0x40 __handle_irq_event_percpu+0x15c/0x308 handle_irq_event_percpu+0x3c/0x90 handle_irq_event+0x54/0x98 handle_level_irq+0xa0/0xd0 handle_irq_desc+0x2c/0x44 generic_handle_domain_irq+0x28/0x34 dpu_mdss_irq+0x90/0xe8 handle_irq_desc+0x2c/0x44 handle_domain_irq+0x54/0x80 gic_handle_irq+0xd4/0x148 call_on_irq_stack+0x2c/0x54 do_interrupt_handler+0x4c/0x64 el1_interrupt+0x30/0xd0 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x78/0x7c arch_local_irq_enable+0xc/0x14 cpuidle_enter+0x44/0x5c do_idle+0x248/0x268 cpu_startup_entry+0x30/0x48 rest_init+0x188/0x19c arch_call_rest_init+0x1c/0x28 start_kernel+0x704/0x744 __primary_switched+0xc0/0xc8Fixes: 78d9b458cc21 ("drm/msm/dpu: Add CRC support for DPU") Signed-off-by: Rob Clark robdclark@chromium.org
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index 0ae397044310..80c0ae688734 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -182,21 +182,19 @@ static int dpu_crtc_get_crc(struct drm_crtc *crtc) { struct dpu_crtc_state *crtc_state; struct dpu_crtc_mixer *m;
u32 *crcs;
u32 crcs[CRTC_DUAL_MIXERS]; int i = 0; int rc = 0; crtc_state = to_dpu_crtc_state(crtc->state);
crcs = kcalloc(crtc_state->num_mixers, sizeof(*crcs), GFP_KERNEL);if (!crcs)return -ENOMEM;
static_assert(ARRAY_SIZE(crcs) == ARRAY_SIZE(crtc_state->mixers));Getting a C90 compiler warning for static_assert():
In file included from ./include/linux/bits.h:22, from ./include/linux/bitops.h:6, from ./include/linux/kernel.h:12, from ./include/linux/list.h:9, from ./include/linux/wait.h:7, from ./include/linux/wait_bit.h:8, from ./include/linux/fs.h:6, from ./include/linux/debugfs.h:15, from drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:10: drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c: In function‘dpu_crtc_get_crc’: ./include/linux/build_bug.h:78:41: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement] 78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg) | ^~~~~~~~~~~~~~ ./include/linux/build_bug.h:77:34: note: in expansion of macro ‘__static_assert’ 77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr) | ^~~~~~~~~~~~~~~ drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c:192:2: note: in expansion of macro ‘static_assert’ 192 | static_assert(ARRAY_SIZE(crcs) == ARRAY_SIZE(crtc_state->mixers)); | ^~~~~~~~~~~~~
Can be fixed by moving the static_assert() before `crtc_state = ...`
I was trying to avoid moving that because I've seen tools flag things like that as use-before-init before. But I guess I can use BUILD_BUG_ON() instead.
BR, -R
Thanks,
Jessica Zhang
/* Skip first 2 frames in case of "uncooked" CRCs */ if (crtc_state->crc_frame_skip_count < 2) { crtc_state->crc_frame_skip_count++;
goto cleanup;
return 0; } for (i = 0; i < crtc_state->num_mixers; ++i) {@@ -210,16 +208,12 @@ static int dpu_crtc_get_crc(struct drm_crtc *crtc)
if (rc) { DRM_DEBUG_DRIVER("MISR read failed\n");
goto cleanup;
return rc; } }
rc = drm_crtc_add_crc_entry(crtc, true,
return drm_crtc_add_crc_entry(crtc, true, drm_crtc_accurate_vblank_count(crtc), crcs);
-cleanup:
kfree(crcs);return rc;}
static bool dpu_crtc_get_scanout_position(struct drm_crtc *crtc,