On 02/20/2017 03:10 PM, Dalon Westergreen wrote:
On Mon, 2017-02-20 at 10:07 +0100, Marek Vasut wrote:
On 02/18/2017 02:34 AM, Dalon Westergreen wrote:
When CSEL=0x0 the socfpga bootrom does not touch the clock configuration for the device. This can lead to a boot failure on warm resets. This patch disables warm resets when CSEL=0. This results in the clock and pll configurations being reset on any reset issued when CSEL=0.
Signed-off-by: Dalon Westergreen dwesterg@gmail.com
What about my suggestion for V2 about just loading function pointer into the reset jump address register ?
Frankly, i really dont like relying on the existence of a snippet of code in the onchip ram being untouched to ensure a reboot/reset will occur for this csel=0 case. i am certain this case is rarely used, and confident that it isnt being used while trying to preserve sdram contents.
Well, you already rely on such snippet, it's SPL. If you corrupt SPL and do warm reset, your system hangs, I had that multiple times :)
the downside is that the scorecard is reset every boot. so the bootrom will retry all the spl images again resulting in possibly longer boot times.
Is that significant ?
The other is that things like sdram content preservation is not likely to work or the csel=0 case (but as i mentioned, i dont see this used often in cyclone5, and never have i seen it when csel=0).
OK, I didn't see this requirement yet.
btw --- missing before the changelog, without it the changelog will land in git history.
Thanks
Changes in v3:
- Change implementation to rely on cold reset for CSEL=0. Which is a much simpler approach to dealing with this special case during boot.
Changes in v2:
- Fix checkpatch issues predominently due to whitespace issues
arch/arm/mach-socfpga/include/mach/system_manager.h | 3 +++ arch/arm/mach-socfpga/misc.c | 13 ++++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-socfpga/include/mach/system_manager.h b/arch/arm/mach-socfpga/include/mach/system_manager.h index c45edea..c9c0b33 100644 --- a/arch/arm/mach-socfpga/include/mach/system_manager.h +++ b/arch/arm/mach-socfpga/include/mach/system_manager.h @@ -137,6 +137,9 @@ struct socfpga_system_manager {
#define SYSMGR_SDMMC_DRVSEL_SHIFT 0
+#define SYSMGR_BOOTINFO_CSEL_MASK 0x18 +#define SYSMGR_BOOTINFO_CSEL_LSB 3
/* EMAC Group Bit definitions */ #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_GMII_MII 0x0 #define SYSMGR_EMACGRP_CTRL_PHYSEL_ENUM_RGMII 0x1 diff --git a/arch/arm/mach-socfpga/misc.c b/arch/arm/mach-socfpga/misc.c index dd6b53b..9792138 100644 --- a/arch/arm/mach-socfpga/misc.c +++ b/arch/arm/mach-socfpga/misc.c @@ -356,6 +356,7 @@ static uint32_t iswgrp_handoff[8]; int arch_early_init_r(void) { int i;
unsigned int csel;
/*
- Write magic value into magic register to unlock support for
@@ -363,8 +364,18 @@ int arch_early_init_r(void) * value to be written into the register by the bootloader, so * to support that old code, we write it here instead of in the * reset_cpu() function just before resetting the CPU.
** For CSEL = 0 we do not want to enable warm resets to ensure that* on reset the clocks and plls are reset to their default statesas
* the bootrom, for CSEL=0, leaves the clocks untouched. If theclocks
* and plls are not reset, the bootrom will fail to load the splimage. */
- writel(0xae9efebc, &sysmgr_regs->romcodegrp_warmramgrp_enable);
- csel = (readl(&sysmgr_regs->bootinfo) & SYSMGR_BOOTINFO_CSEL_MASK)
SYSMGR_BOOTINFO_CSEL_LSB;- if (csel)
writel(0xae9efebc, &sysmgr_regs-romcodegrp_warmramgrp_enable);
for (i = 0; i < 8; i++) /* Cache initial SW setting regs */ iswgrp_handoff[i] = readl(&sysmgr_regs->iswgrp_handoff[i]);