[PATCH v2 1/8] ARM: add mach-asm9260

[Arnd Bergmann]

On Wednesday 24 September 2014 11:25:42 Russell King - ARM Linux wrote:
> On Wed, Sep 24, 2014 at 11:56:03AM +0200, Oleksij Rempel wrote:
> > Am 24.09.2014 um 11:43 schrieb Russell King - ARM Linux:
> > > The "why" is in the text from your oops dump.  That's precisely /why/ we
> > > print that text - so that we know /why/ the fault happened.
> > 
> > Here is oops message:
> > http://pastebin.com/qYWeAyfV
> > 
> > i can avoid this oops by setting size at least 0x2000 per register
> > range. Do it mean my TLB supports only 8 KiB pages?
> 
> No, it has nothing to do with the TLB.
> 
> Unable to handle kernel paging request at virtual address c2802174
> pgd = c0004000
> [c2802174] *pgd=21805811, *pte=00000000, *ppte=00000000
> Internal error: Oops: 7 [#1] PREEMPT ARM
> 
> The number after the Oops: is the FSR value, which means "page translation
> fault", and sure enough, the pgd/pte values show that there is no page
> table entry at the faulting address.
> 
> That's odd, because ioremap() aligns the size of the requested mapping up
> to a multiple of the page size, and inserts page table entries according
> to the rounded size.
> 
> Where are you calling ioremap(), iounmap() etc?  IOW, please show your
> code for this.

It's the clock driver from patch 5. It starts out with an ioremap of
the clock controller node:

+               acc: clock-controller at 80040000 {
+                       compatible = "alphascale,asm9260-clock-controller";
+                       #clock-cells = <1>;
+                       clocks = <&osc24m>;
+                       reg = <0x80040000 0x500>;
+               };

Oh, and there is the bug:

+       /* check for errors on leaf clocks */
+       for (n = 0; n < MAX_CLKS; n++) {
+               if (!IS_ERR(clks[n]))
+                       continue;
+
+               pr_err("%s: Unable to register leaf clock %d\n",
+                               np->full_name, n);
+               goto fail;
+       }
+
+       /* register clk-provider */
+       clk_data.clks = clks;
+       clk_data.clk_num = MAX_CLKS;
+       of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
+fail:
+       iounmap(base);
+}

There should be a 'return' in front of the 'fail:', otherwise it
get unmapped unconditionally.

	Arnd