From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] USB: set device dma_mask without reference to global data
Date: Wed, 08 May 2013 16:42:04 -0600 [thread overview]
Message-ID: <518AD4BC.6090009@wwwdotorg.org> (raw)
In-Reply-To: <CAL411-pY_i19otiE2pLux6eR_OFHhfhK=+6BF=H6wABDsGCP6Q@mail.gmail.com>
On 05/07/2013 08:54 PM, Peter Chen wrote:
>>
>> This probably could be initialized from some DT property. However,
>> there's no such property defined right now, and considering that DT is
>> supposed to be an ABI, we'd always need the code in this patch as a
>> fallback for DTs that were created before any such property was defined.
>>
>> Equally, since the data is SoC-specific rather than board-specific, and
>> is even fairly unlikely to vary between SoC versions since these values
>> are all 0xffffffff anyway, I don't really see much point in putting it
>> into DT, rather than just putting the static data into the driver.
>
> I mean there is already dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> at function of_platform_device_create, why can't add
> dev->dev.dma_mask = &dev->dev.coherent_dma_mask after that?
>
> If DT core can do above things, can we delete dma_mask assignment
> at every driver?
Perhaps. However, such a change has a much larger potential for regressions.
I would suggest going with the current patch for 3.10 and any later
backports in order to reduce risk. We can revisit better cleanup for
later kernels.
next prev parent reply other threads:[~2013-05-08 22:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-07 22:53 [PATCH] USB: set device dma_mask without reference to global data Stephen Warren
2013-05-07 23:04 ` Greg Kroah-Hartman
2013-05-07 23:42 ` Arnd Bergmann
2013-05-08 14:14 ` Alan Stern
2013-05-08 15:10 ` Arnd Bergmann
2013-05-09 21:33 ` Russell King - ARM Linux
2013-05-08 1:13 ` Peter Chen
2013-05-08 2:26 ` Stephen Warren
2013-05-08 2:54 ` Peter Chen
2013-05-08 7:11 ` Matthijs Kooijman
2013-05-08 7:28 ` Matthijs Kooijman
2013-05-08 13:50 ` Rob Herring
2013-05-08 14:07 ` Arnd Bergmann
2013-05-08 7:24 ` Arnd Bergmann
2013-05-09 21:39 ` Russell King - ARM Linux
2013-05-08 22:42 ` Stephen Warren [this message]
2013-05-09 21:36 ` Russell King - ARM Linux
2013-05-08 5:11 ` Tony Prisk
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