HDLCD crashes with 6d910bfa809e

[liviu.dudau at arm.com]

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:
> > Hi Liviu,
> > 
> > On 07/06/16 14:35, liviu.dudau at arm.com wrote:
> > >On Tue, Jun 07, 2016 at 01:06:00PM +0100, Robin Murphy wrote:
> > >>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
> 
> > 
> > Oh well...
> > 
> > Robin.
> > 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯