HDLCD crashes with 6d910bfa809e

On Tue, Jun 07, 2016 at 03:14:04PM +0100, liviu.dudau at arm.com wrote:

On Tue, Jun 07, 2016 at 03:11:14PM +0100, Robin Murphy wrote:

quoted

Hi Liviu,

On 07/06/16 14:35, liviu.dudau at arm.com wrote:

quoted

On Tue, Jun 07, 2016 at 01:06:00PM +0100, Robin Murphy wrote:

quoted

Having just inadvertently merged -next into my working branch, I find
dev6d910bfa809e ("drm/hlcd: Use lockless gem BO free callback") adversely
affecting my board's ability to boot ;)

Since I (intentionally) don't have sufficient CMA to create a framebuffer,
drm_gem_cma_create() fails, unconditionally calls the now-NULL
drm->driver->gem_free_object() in its cleanup path, and fiery death
ensues...

Thanks for reporting this. What other changes other than reducing the CMA
allocation size do you have that I might need in order to reproduce this?

I've just confirmed a plain checkout of next-20160602, using arm64 defconfig
+ DRM + HDLCD + TDA998X and CMA_SIZE_MBYTES=1, booted on a Juno, does the
job:

[    3.032402] hdlcd 7ff60000.hdlcd: bound 0-0070 (ops tda998x_ops)
[    3.038388] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    3.044970] [drm] No driver support for vblank timestamp query.
[    3.076973] hdlcd 7ff60000.hdlcd: failed to allocate buffer with size
7680000
[    3.084081] Bad mode in Synchronous Abort handler detected, code
0x86000004 -- IABT (current EL)
[    3.092815] CPU: 3 PID: 6 Comm: kworker/u12:0 Not tainted
4.7.0-rc1-next-20160602 #686
[    3.100682] Hardware name: ARM Juno development board (r1) (DT)
[    3.106567] Workqueue: deferwq deferred_probe_work_func
[    3.111761] task: ffff8009768a3e80 ti: ffff8009768e8000 task.ti:
ffff8009768e8000
[    3.119198] PC is at 0x0
[    3.121720] LR is at drm_gem_cma_create+0x128/0x130
...and so on.

Today's -next, on the other hand, dodges the bullet entirely:

[    2.903645] [drm] found ARM HDLCD version r0p0
[    2.908122] hdlcd 7ff60000.hdlcd: master bind failed: -22
[    2.913505] tda998x: probe of 0-0070 failed with error -22
[    2.919141] [drm] found ARM HDLCD version r0p0
[    2.923609] hdlcd 7ff50000.hdlcd: master bind failed: -22
[    2.928991] tda998x: probe of 0-0071 failed with error -22

Yes, if fails in of_reserved_mem_device_init(). Tracking now to see
which of the conditions at line 311 are the culprits.

Bah, discard the line number, old cached version in my editor.

Liviu

Best regards,
Liviu

quoted

Oh well...

Robin.

-- 
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