Re: Recent git kernels and OSK

[Dirk Behme <dirk.behme@googlemail.com>]

Dirk Behme wrote:
> Doing some more debugging (with low level debug disabled now) shows that 
> at least until "ARM: OMAP: DSPGW: mailbox log cleanup" [1] everything is 
> okay. Then, with all changes including "ARM: OMAP: DSPGW: Peripheral 
> (kfunc) control" [2] it seems to be broken.

After some additional hours of debugging it's a really
simple bug: A strcmp() mismatch which results in
omap_dsp->mbox being a NULL pointer.

In mach-omap1/mailbox.c the mailbox name is .name = "DSP"
while in plat-omap/dsp/dsp_core.c function  dsp_mbox_init()
asks for "dsp". omap2 is correct, there .name is "dsp".

Patch follows.

There are still some open questions:

Mailbox related:

* Why does

if (IS_ERR(omap_dsp->mbox)) {

in arch/arm/plat-omap/dsp/dsp_core.c in dsp_mbox_init()
doesn't catch NULL pointer (omap_dsp->mbox == NULL)?

- Why does system crash later if omap_dsp->mbox being NULL
is caught correctly? E.g. using

if (omap_dsp->mbox == NULL) {

instead of IS_ERR above results in

...
<3>failed to get mailbox handler for DSP.
<7>omapdsp: unmapping in ARM MMU, v=0xe0fff000, sz=0x1000
<1>Unable to handle kernel paging request at virtual address
b0000ffc
...

LowLevel debug related:

- Why does LowLevel debug only works if omap_writew(reg,
SOFT_REQ_REG) is disabled in mach-omap1/clock.c ?

Cheers

Dirk