[RFC PATCH 3/3] libdrm: user mode helper for ipvr drm driver

Jiang, Fei fei.jiang at intel.com
Thu Oct 16 17:36:56 PDT 2014


Thanks for Emil's suggestion. You are right, we need make sure structure size aligned on 8 bytes, which is important for 32bit-64bit compatible case.

Fei
-----Original Message-----
From: Emil Velikov [mailto:emil.l.velikov at gmail.com] 
Sent: Thursday, October 16, 2014 11:20 PM
To: Cheng, Yao; intel-gfx at lists.freedesktop.org
Cc: emil.l.velikov at gmail.com; Jiang, Fei; dri-devel at lists.freedesktop.org; Vetter, Daniel
Subject: Re: [RFC PATCH 3/3] libdrm: user mode helper for ipvr drm driver

On 16/10/14 15:33, Cheng, Yao wrote:
> Hi Emil,
> Sorry, what do you mean by "correctly aligned"? does it mean the paddings in this data structure?
> 
Afaict for compatibility reasons the struct size have to be "aligned"
(multiple of 8 bytes), or if you prefer - the struct is missing the required padding :) I've only skimmed through the patch so it may be that other structs are having this issue.

Cheers,
Emil

>> -----Original Message-----
>> From: Emil Velikov [mailto:emil.l.velikov at gmail.com]
>> Sent: Wednesday, October 15, 2014 5:24 PM
>> To: Cheng, Yao; intel-gfx at lists.freedesktop.org
>> Cc: emil.l.velikov at gmail.com; Jiang, Fei; 
>> dri-devel at lists.freedesktop.org; Vetter, Daniel
>> Subject: Re: [RFC PATCH 3/3] libdrm: user mode helper for ipvr drm 
>> driver
>>
>> Hi Yao,
>>
>> struct drm_ipvr_gem_userptr does not seem to be correctly aligned - 
>> is that intentional ? Might be worth checking if anything else in 
>> ipvr_drm.h and ipvr_bufmgr.h is in the same boat.
>>
>> Cheers,
>> Emil
>>



More information about the dri-devel mailing list