RE: [linux-keystone] [PATCH v2] drivers: cma: fix addressing on PAEmachines

From: Andrianov, Vitaly
Date: Tue Dec 04 2012 - 16:03:13 EST




> -----Original Message-----
> From: Michal Nazarewicz [mailto:mpn@xxxxxxxxxx] On Behalf Of Michal
> Nazarewicz
> Sent: Tuesday, December 04, 2012 2:05 PM
> To: Andrianov, Vitaly; Shilimkar, Santosh
> Cc: m.szyprowski@xxxxxxxxxxx; kyungmin.park@xxxxxxxxxxx; arnd@xxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; linux-keystone@xxxxxxxxxxx - Linux
> developers for Keystone family of devices (May contain non-TIers);
> Chemparathy, Cyril
> Subject: Re: [linux-keystone] [PATCH v2] drivers: cma: fix addressing
> on PAE machines
>
> > On Tuesday 04 December 2012 06:37 PM, Michal Nazarewicz wrote:
> >> They are all related to the very same issue, and what the whole
> patch
> >> does is change the type used to store physical addresses from
> >> unsigned long to phys_addr_t. This is really a single change.
>
> On Tue, Dec 04 2012, Santosh Shilimkar wrote:
> > Thanks for clarification. 64 bit alignment fix and the allocation
> > range checks can be two separate fixes and that is exactly what
> change
> > log describes. You have a last say though :-) No problem if you want
> > to commit the patch as is.
>
> I don't have strong feelings on this one, but I feel like it's really a
> single change which manifests itself in a few ways. If this is
> confusing, maybe commit message could be improved, to something like:
>
> ------------- >8 ------------------------------------------------------
> -
> drivers: cma: represent physicall addresses as phys_addr_t
>
> This commit changes the CMA early initialisation code to use
> phys_addr_t for representing physical addresses instead of unsigned
> long.
>
> Without this change, among other things, dma_declare_contiguous()
> simply discards any memory regions whose address is not represtible as
> unsigned long.
>
> This is a problem on 32-bit PAE machines where unsigned long is 32-bit
> but physical address space is larger.
> ------------- 8< ------------------------------------------------------
> -
>
> Vitaly, if you could resend with that description, it would be awesome,
> and sorry for so much trouble in what appears to be a trivial patch. :P
>

Sure, I'll do that.

> --
> Best regards, _ _
> .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
> ..o | Computer Science, MichaÅ âmina86â Nazarewicz (o o)
> ooo +----<email/xmpp: mpn@xxxxxxxxxx>--------------ooO--(_)--Ooo--

Regards,
Vitaly

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