[U-Boot] [PATCH] blk: Remove various places that do flush cache after read

[York Sun]

On 08/21/2017 08:42 PM, Bin Meng wrote:
> All these places seem to inherit the codes from the MMC driver where
> a FIXME was put in the comment. However the correct operation after
> read should be cache invalidate, not flush.
> 
> The underlying drivers should be responsible for the cache operation.
> Remove these codes completely.
> 
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
> 
>   arch/arm/cpu/armv8/fsl-layerscape/ppa.c | 15 ---------------
>   board/toradex/common/tdx-cfg-block.c    |  2 --
>   cmd/mmc.c                               |  2 --
>   drivers/block/blk-uclass.c              |  3 ---
>   drivers/block/blk_legacy.c              |  3 ---
>   drivers/net/fm/fm.c                     |  2 --
>   drivers/net/phy/cortina.c               |  2 --
>   drivers/qe/qe.c                         |  2 --
>   8 files changed, 31 deletions(-)
> 
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/ppa.c b/arch/arm/cpu/armv8/fsl-layerscape/ppa.c
> index 24ddb5d..bbf8bba 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/ppa.c
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/ppa.c
> @@ -107,9 +107,6 @@ int ppa_init(void)
>   		return -EIO;
>   	}
>   
> -	/* flush cache after read */
> -	flush_cache((ulong)fitp, cnt * 512);
> -

NACK here.


>   	ret = fdt_check_header(fitp);
>   	if (ret) {
>   		free(fitp);
> @@ -134,9 +131,6 @@ int ppa_init(void)
>   	}
>   	debug("Read PPA header to 0x%p\n", ppa_hdr_ddr);
>   
> -	/* flush cache after read */
> -	flush_cache((ulong)ppa_hdr_ddr, cnt * 512);
> -
>   	ppa_esbc_hdr = (uintptr_t)ppa_hdr_ddr;
>   #endif
>   
> @@ -164,9 +158,6 @@ int ppa_init(void)
>   		return -EIO;
>   	}
>   
> -	/* flush cache after read */
> -	flush_cache((ulong)ppa_fit_addr, cnt * 512);
> -
>   #elif defined(CONFIG_SYS_LS_PPA_FW_IN_NAND)
>   	struct fdt_header fit;
>   
> @@ -208,9 +199,6 @@ int ppa_init(void)
>   	}
>   	debug("Read PPA header to 0x%p\n", ppa_hdr_ddr);
>   
> -	/* flush cache after read */
> -	flush_cache((ulong)ppa_hdr_ddr, fw_length);
> -
>   	ppa_esbc_hdr = (uintptr_t)ppa_hdr_ddr;
>   #endif
>   
> @@ -232,9 +220,6 @@ int ppa_init(void)
>   		       CONFIG_SYS_LS_PPA_FW_ADDR);
>   		return -EIO;
>   	}
> -
> -	/* flush cache after read */
> -	flush_cache((ulong)ppa_fit_addr, fw_length);
>   #else
>   #error "No CONFIG_SYS_LS_PPA_FW_IN_xxx defined"
>   #endif

Hold on for ppa.c. We need to flush the cache after reading PPA image 
and it header after loading. These images need to be flushed into main 
memory. I will need to confirm with our team if we can remove flushing here.

York