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From: Tomasz Stanislawski <t.stanislaws@samsung.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
	airlied@redhat.com, m.szyprowski@samsung.com,
	kyungmin.park@samsung.com, laurent.pinchart@ideasonboard.com,
	sumit.semwal@linaro.org, inki.dae@samsung.com,
	daniel.vetter@ffwll.ch, rob@ti.com, pawel@osciak.com,
	linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org,
	jy0922.shim@samsung.com, sw0312.kim@samsung.com,
	dan.j.williams@intel.com, linux-doc@vger.kernel.org
Subject: Re: [PATCH v2 1/2] dma-buf: add reference counting for exporter module
Date: Thu, 09 Aug 2012 16:54:41 +0200	[thread overview]
Message-ID: <5023CF31.4010209@samsung.com> (raw)
In-Reply-To: <20120809142346.GA17402@kroah.com>

Hi Greg,

On 08/09/2012 04:23 PM, Greg KH wrote:
> On Thu, Aug 09, 2012 at 11:36:21AM +0200, Tomasz Stanislawski wrote:
>> This patch adds reference counting on a module that exported dma-buf and
>> implements its operations. This prevents the module from being unloaded while
>> DMABUF file is in use.
> 
> Why force all of the modules to be changed "by hand", and not just do
> this automatically by changing the register function to include the
> THIS_MODULE macro in it?  Much like the pci_register_driver() function
> is implemented in include/linux/pci.h?

Thank you for the hint.

The owner field belongs to dma_buf_ops structure that is often a 'const'
entity. Therefore owner field would have to be moved to 'struct dma_buf'
to avoid 'deconstification' issues.

Regards,
Tomasz Stanislawski

> 
> That makes it impossible for driver authors to get it wrong, which is
> always a good sign of a correct api.
> 
> thanks,
> 
> greg k-h
> 


  reply	other threads:[~2012-08-09 14:54 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-09  9:36 [PATCH v2 0/2] Enhance DMABUF with reference counting for exporter module Tomasz Stanislawski
2012-08-09  9:36 ` [PATCH v2 1/2] dma-buf: add " Tomasz Stanislawski
2012-08-09 14:23   ` Greg KH
2012-08-09 14:54     ` Tomasz Stanislawski [this message]
2012-08-09  9:36 ` [PATCH v2 2/2] drm: set owner field to for all DMABUF exporters Tomasz Stanislawski

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