Tero Kristo <t-kristo@xxxxxx> writes:
> Without this, CPU0 will crash in the ROM code during wakeup from
> device off. This patch also clears the GIC save area, to prevent
> ROM code from writing garbage to the GIC registers during wakeup.
> The actual GIC restore is done by kernel.
>
> This bug fix applies only to OMAP4460, it is fixed on OMAP4470.
>
> Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
Please create/use PM_ERRATUM flag.
Kevin
> ---
> arch/arm/mach-omap2/omap-wakeupgen.c | 14 ++++++++++++++
> arch/arm/mach-omap2/omap4-sar-layout.h | 1 +
> 2 files changed, 15 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/omap-wakeupgen.c b/arch/arm/mach-omap2/omap-wakeupgen.c
> index c7c4db4..30da299 100644
> --- a/arch/arm/mach-omap2/omap-wakeupgen.c
> +++ b/arch/arm/mach-omap2/omap-wakeupgen.c
> @@ -447,10 +447,24 @@ int __init omap_wakeupgen_init(void)
>
> if (omap_type() == OMAP2_DEVICE_TYPE_GP) {
> sar_base = ioremap(OMAP44XX_SAR_RAM_BASE, SZ_16K);
> + /* Clean GIC SAR area */
> + for (i = SAR_BACKUP_STATUS_OFFSET; i < WAKEUPGENENB_OFFSET_CPU0;
> + i += 4)
> + sar_writel(0, i, 0);
> +
> sar_writel(GIC_ISR_NON_SECURE, ICDISR_CPU0_OFFSET, 0);
> sar_writel(GIC_ISR_NON_SECURE, ICDISR_CPU1_OFFSET, 0);
> for (i = 0; i < max_spi_reg; i++)
> sar_writel(GIC_ISR_NON_SECURE, ICDISR_SPI_OFFSET, i);
> +
> + /*
> + * Set CPU0 GIC backup flag permanently for omap4460,
> + * this is needed because of the ROM code bug that breaks
> + * GIC during wakeup from device off
> + */
> + if (cpu_is_omap446x())
> + __raw_writel(SAR_BACKUP_STATUS_GIC_CPU0,
> + sar_base + SAR_BACKUP_STATUS_OFFSET);
> iounmap(sar_base);
> sar_base = NULL;
> } else {
> diff --git a/arch/arm/mach-omap2/omap4-sar-layout.h b/arch/arm/mach-omap2/omap4-sar-layout.h
> index 0056667..e621c51 100644
> --- a/arch/arm/mach-omap2/omap4-sar-layout.h
> +++ b/arch/arm/mach-omap2/omap4-sar-layout.h
> @@ -88,6 +88,7 @@
> #define ICDISR_CPU0_OFFSET (SAR_BANK3_OFFSET + 0x50c)
> #define ICDISR_CPU1_OFFSET (SAR_BANK3_OFFSET + 0x510)
> #define ICDISR_SPI_OFFSET (SAR_BANK3_OFFSET + 0x514)
> +#define SAR_BACKUP_STATUS_GIC_CPU0 0x1
>
> /* WakeUpGen save restore offset from OMAP44XX_SAR_RAM_BASE */
> #define WAKEUPGENENB_OFFSET_CPU0 (SAR_BANK3_OFFSET + 0x684)
--
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