ARM: OMAP: Fix reprogramming of dpll1 rate
Commit a66cb3454f220f49f900646ebdc76cb943319eb7 (ARM: OMAP: Map SRAM
later on with ioremap_exec()) moved the SRAM init to happen later
to remove a dependency to early SoC detection for map_io.
This broke booting on some boards not using Kconfig option for
OMAP_CLOCKS_SET_BY_BOOTLOADER as the dpll1 reprogramming would
cause the following error:
kernel BUG at arch/arm/plat-omap/sram.c:226!
Internal error: Oops - undefined instruction: 0 [#1] PREEMPT
Modules linked in:
CPU: 0 Not tainted (3.2.0-rc1-e3 #9)
PC is at omap_sram_reprogram_clock+0x28/0x30
LR is at omap1_select_table_rate+0x88/0xb4
pc : [<c001b0c4>] lr : [<c0019f54>] psr: 600000d3
sp : c035bf10 ip : c035bf20 fp : c035bf1c
r10: c035bfd4 r9 : 54029252 r8 : c03f8120
r7 : c0362b50 r6 : 00b71b00 r5 : c03873cc r4 : c0362b40
r3 : 00000000 r2 : c0362b40 r1 : 0000010a r0 : 00002cb0
Flags: nZCv IRQs off FIQs off Mode SVC_32 ISA ARM Segment kernel
Control: 0000317f Table: 10004000 DAC: 00000017
Process swapper (pid: 0, stack limit = 0xc035a270)
Stack: (0xc035bf10 to 0xc035c000)
bf00: c035bf3c c035bf20 c0019f54 c001b0ac
bf20: 00001000 00002cb3 00000004 c035ed4c c035bf74 c035bf40 c033ea24 c0019edc
bf40: c02f526c 00000002 00000015 bc058c9b 93111a16 c035335c 02000000 c035ed4c
bf60: c035ed4c c03f8120 c035bf84 c035bf78 c00194c4 c033e8ec c035bfc4 c035bf88
bf80: c033bc24 c00194a0 c035bf90 c035bf98 00000000 00000000 00000000 00000000
bfa0: 00000001 00000000 c0354678 c035ece4 10004000 103532f4 c035bff4 c035bfc8
bfc0: c0338574 c033b598 00000000 00000000 00000000 c035467c 0000317d c035c03c
bfe0: c0354678 c035ece4 00000000 c035bff8 10008040 c0338508 00000000 00000000
Backtrace:
[<c001b09c>] (omap_sram_reprogram_clock+0x0/0x30) from [<c0019f54>] (omap1_select_table_rate+0x88/0xb4)
[<c0019ecc>] (omap1_select_table_rate+0x0/0xb4) from [<c033ea24>] (omap1_clk_init+0x148/0x334)
r7:c035ed4c r6:00000004 r5:00002cb3 r4:00001000
[<c033e8dc>] (omap1_clk_init+0x0/0x334) from [<c00194c4>] (omap1_init_early+0x34/0x48)
r8:c03f8120 r7:c035ed4c r6:c035ed4c r5:02000000 r4:c035335c
[<c0019490>] (omap1_init_early+0x0/0x48) from [<c033bc24>] (setup_arch+0x69c/0x79c)
[<c033b588>] (setup_arch+0x0/0x79c) from [<c0338574>] (start_kernel+0x7c/0x2f4)
[<c03384f8>] (start_kernel+0x0/0x2f4) from [<10008040>] (0x10008040)
r7:c035ece4 r6:c0354678 r5:c035c03c r4:0000317d
Code: 0a000002 e1a0e00f e12fff13 e89da800 (e7f001f2)
Fix this by adding omap1_clk_late_init() that only reprograms dpll1
if the bootloader rate is less than 60MHz. This also allows removing
of the OMAP_CLOCKS_SET_BY_BOOTLOADER option.
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap1/clock_data.c b/arch/arm/mach-omap1/clock_data.c
index 92400b9..1297bb5 100644
--- a/arch/arm/mach-omap1/clock_data.c
+++ b/arch/arm/mach-omap1/clock_data.c
@@ -767,6 +767,15 @@
.clk_disable_unused = omap1_clk_disable_unused,
};
+static void __init omap1_show_rates(void)
+{
+ pr_notice("Clocking rate (xtal/DPLL1/MPU): "
+ "%ld.%01ld/%ld.%01ld/%ld.%01ld MHz\n",
+ ck_ref.rate / 1000000, (ck_ref.rate / 100000) % 10,
+ ck_dpll1.rate / 1000000, (ck_dpll1.rate / 100000) % 10,
+ arm_ck.rate / 1000000, (arm_ck.rate / 100000) % 10);
+}
+
int __init omap1_clk_init(void)
{
struct omap_clk *c;
@@ -835,9 +844,12 @@
/* We want to be in syncronous scalable mode */
omap_writew(0x1000, ARM_SYSST);
-#ifdef CONFIG_OMAP_CLOCKS_SET_BY_BOOTLOADER
- /* Use values set by bootloader. Determine PLL rate and recalculate
- * dependent clocks as if kernel had changed PLL or divisors.
+
+ /*
+ * Initially use the values set by bootloader. Determine PLL rate and
+ * recalculate dependent clocks as if kernel had changed PLL or
+ * divisors. See also omap1_clk_late_init() that can reprogram dpll1
+ * after the SRAM is initialized.
*/
{
unsigned pll_ctl_val = omap_readw(DPLL_CTL);
@@ -862,25 +874,10 @@
}
}
}
-#else
- /* Find the highest supported frequency and enable it */
- if (omap1_select_table_rate(&virtual_ck_mpu, ~0)) {
- printk(KERN_ERR "System frequencies not set. Check your config.\n");
- /* Guess sane values (60MHz) */
- omap_writew(0x2290, DPLL_CTL);
- omap_writew(cpu_is_omap7xx() ? 0x3005 : 0x1005, ARM_CKCTL);
- ck_dpll1.rate = 60000000;
- }
-#endif
propagate_rate(&ck_dpll1);
/* Cache rates for clocks connected to ck_ref (not dpll1) */
propagate_rate(&ck_ref);
- printk(KERN_INFO "Clocking rate (xtal/DPLL1/MPU): "
- "%ld.%01ld/%ld.%01ld/%ld.%01ld MHz\n",
- ck_ref.rate / 1000000, (ck_ref.rate / 100000) % 10,
- ck_dpll1.rate / 1000000, (ck_dpll1.rate / 100000) % 10,
- arm_ck.rate / 1000000, (arm_ck.rate / 100000) % 10);
-
+ omap1_show_rates();
if (machine_is_omap_perseus2() || machine_is_omap_fsample()) {
/* Select slicer output as OMAP input clock */
omap_writew(omap_readw(OMAP7XX_PCC_UPLD_CTRL) & ~0x1,
@@ -925,3 +922,21 @@
return 0;
}
+
+#define OMAP1_DPLL1_SANE_VALUE 60000000
+
+void __init omap1_clk_late_init(void)
+{
+ if (ck_dpll1.rate >= OMAP1_DPLL1_SANE_VALUE)
+ return;
+
+ /* Find the highest supported frequency and enable it */
+ if (omap1_select_table_rate(&virtual_ck_mpu, ~0)) {
+ pr_err("System frequencies not set, using default. Check your config.\n");
+ omap_writew(0x2290, DPLL_CTL);
+ omap_writew(cpu_is_omap7xx() ? 0x3005 : 0x1005, ARM_CKCTL);
+ ck_dpll1.rate = OMAP1_DPLL1_SANE_VALUE;
+ }
+ propagate_rate(&ck_dpll1);
+ omap1_show_rates();
+}