Olof Johansson wrote at Tuesday, October 18, 2011 12:18 PM:
> From: Jon Mayo <[email protected]>
>
> Tegra2 hangs if APB registers are accessed from the cpu during an
> apb dma operation. The workaround is to use apb dma to read/write the
> registers instead.
...
> +++ b/arch/arm/mach-tegra/apbio.c
...
> +#ifdef CONFIG_TEGRA_SYSTEM_DMA
...
> +static inline u32 apb_readl(unsigned long offset)
...
> +static inline void apb_writel(u32 value, unsigned long offset)
...
> +#else
> +static inline u32 apb_readl(unsigned long offset)
...
> +static inline void apb_writel(u32 value, unsigned long offset)
...
> +#endif
> +
> +u32 tegra_apb_readl(unsigned long offset)
> +{
> + return apb_readl(offset);
> +}
> +
> +void tegra_apb_writel(u32 value, unsigned long offset)
> +{
> + apb_writel(value, offset);
> +}
Why not just make the actual implementations use the exported names, and
have them not be static inline? That way, you avoid the extra function
wrapping them.
> +void tegra_init_apb_dma(void)
> +{
> +#ifdef CONFIG_TEGRA_SYSTEM_DMA
> + tegra_apb_dma = tegra_dma_allocate_channel(TEGRA_DMA_MODE_ONESHOT |
> + TEGRA_DMA_SHARED);
> + if (!tegra_apb_dma) {
> + pr_err("%s: can not allocate dma channel\n", __func__);
It seems like that should be a lot more noisy if the result is potential
HW hangs. Same for the other error below.
--
nvpublic
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