[PATCH] qemu: aspeed_smc: Calculate checksum on normal DMA

[Cédric Le Goater]

Hello Christian,

On 11/12/18 3:22 PM, Christian Svensson wrote:
> This patch adds the missing checksum calculation on normal DMA transfer.
> According to the datasheet this is how the SMC should behave.

The datasheet is not very clear on the topic. 

Bit 2 of FMC80 says :

	CheckSum Calculation Only
	0: Normal DMA operation
	1: Checksum accumulation only
	This bit is valid only when the DMA direction = 0
 
and one could understand that under Normal DMA operation, there is 
no Checksum accumulation. 

Anyhow, I am ok for adding the change. 

> Verified on AST1250 that the hardware matches the behaviour.

Did you check under u-boot, did you add DMA support to the Linux driver ? 
do you have a firmware doing so you could share ? I would like to check
for the ast2500.

Thanks,

C. 


> Signed-off-by: Christian Svensson <bluecmd at google.com>
> ---
>  hw/ssi/aspeed_smc.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c
> index 55ceffe100..0dc22e44cf 100644
> --- a/hw/ssi/aspeed_smc.c
> +++ b/hw/ssi/aspeed_smc.c
> @@ -871,6 +871,7 @@ static void aspeed_smc_dma_rw(AspeedSMCState *s)
>          s->regs[R_DMA_FLASH_ADDR] += 4;
>          s->regs[R_DMA_DRAM_ADDR] += 4;
>          s->regs[R_DMA_LEN] -= 4;
> +        s->regs[R_DMA_CHECKSUM] += data;
>      }
>  }
>  
>