[U-Boot] [PATCH v2] mx31: Setup AIPS registers

Dirk Behme
2012-03-01T06:30:18Z

On 29.02.2012 21:56, Fabio Estevam wrote:
> On Wed, Feb 29, 2012 at 5:03 PM, Dirk Behme <dirk.behme@googlemail.com> wrote:
>
>> Hmm, sorry if I missed anything because it's too late here. But:
>>
>> Why now an U-Boot patch? What's about the kernel patch you sent earlier?
>>
>> http://www.spinics.net/lists/arm-kernel/msg162109.html
>
> The motivation for this patch came after I was debugging audio
> playback on mx31pdk.
>
> I noticed that audio only worked when I used Redboot.
>
> Comparing the sources of Redboot and U-boot I saw that the aips
> registers were not set.
>
> Setting them in U-boot allowed me to get audio playback working.
>
> Why did I send the aips setting to the kernel? Well, it is not always
> possible for customers to change the bootloader.
>
> In case the bootloader does not set aips, then this should be done in
> the kernel.
>
> You can also think on the possibility of someone using the mainline
> U-boot with a kernel that does not set aips, so the safest thing is to
> have such settings in the bootloader and in the kernel.

Ah, thanks for the explanation! :)

This does mean that you want the change in both, U-Boot and kernel, correct?

>> And why don't you try to create some common parts with
>>
>> http://git.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=commitdiff;h=f2f7745825ee5f6bae5b480c8e9c6641a7ffa73b
>
> I thought about that, but I realized the AIPS settings were not
> exactly the same. My main goal at this point was to get the aips
> settings in mx31, but I can work on factoring out this code later.

Yes, we definitely should look at which parts are common. I haven't
looked at the details, but at least the register definitions [1] are the
same?

Best regards

Dirk

[1]

+/* AIPS registers */
+struct aipstz_regs {
+ u32 mprot0;
+ u32 mprot1;
+ u32 rsvd[0xe];
+ u32 opacr0;
+ u32 opacr1;
+ u32 opacr2;
+ u32 opacr3;
+ u32 opacr4;
+};
+