From mboxrd@z Thu Jan  1 00:00:00 1970
From: "'gregkh@linuxfoundation.org'" <gregkh@linuxfoundation.org>
Subject: Re: change kmalloc into vmalloc for large memory
	allocations
Date: Fri, 28 Feb 2014 08:33:04 -0800
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To: "Wang, Yalin" <Yalin.Wang@sonymobile.com>
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On Fri, Feb 28, 2014 at 05:20:08PM +0800, Wang, Yalin wrote:
> Hi  
> 
> 
> Yeah,  
> Dma buffer must be allocated by kmalloc,
> 
> But the modules I list should can all be changed to use
> vmalloc, because the buffer is only used by software,
> Not by any hardware .

Are you sure about that?  The USB gadget driver needs DMA memory from
what I can tell, have you tried your change out on a system that does
not allow the USB controller to access non-DMA memory?

And I agree with Steve, just fix the individual drivers, don't do a
"hidden" change of where the memory is allocated from, that's not a good
idea and will cause problems later.

greg k-h