Hi,
On 03/28/2014 03:15 AM, Wills Wang wrote:
> In sun5i/sun6i/sun7i, the maximum of DMA DES bits are 16, the maximum buffer
> size is (1 << 15)
No the maximum buffer size is 2 ^ 16, which gets expressed as a buf-size of 0
in the register. I've added a printf to ensure the maximum buf size actually
ever gets used and it does and doing 64k transfers works fine.
Note that this also is what the u-boot code has been doing from day one, and
what the upstream kernel code does.
Regards,
Hans
, so the shift bits should be (MMC_MAX_DMA_DES_BIT - 1).
> #define SDXC_DES_NUM_SHIFT (MMC_MAX_DMA_DES_BIT - 1)
> #define SDXC_DES_BUFFER_MAX_LEN (1U << SDXC_DES_NUM_SHIFT)
>
> On 03/28/2014 04:40 AM, Hans de Goede wrote:
>>>> >>@@ -250,7 +250,7 @@
>>>> >> #define SDXC_IDMA_ERR (SDXC_IDMACFatalBusErr|SDXC_IDMACDesInvalid \
>>>> >> |SDXC_IDMACCardErrSum|SDXC_IDMACAbnormalIntSum)
>>>> >>
>>>> >>-#define SDXC_DES_NUM_SHIFT (MMC_MAX_DMA_DES_BIT)
>>>> >>+#define SDXC_DES_NUM_SHIFT (MMC_MAX_DMA_DES_BIT - 1)
>>>> >> #define SDXC_DES_BUFFER_MAX_LEN (1U << SDXC_DES_NUM_SHIFT)
>>>> >> struct sunxi_mmc_idma_des {
>>>> >> u32 config;
>> This chunk is non-sense and should not I repeat NOT be applied.
>
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