Re: [PATCH] MdeModulePkg/EmmcDxe: Use Trim instead of Erase for EraseBlocks

[Jun Nie <jun.nie@linaro.org>]

On 2017年08月08日 10:04, Hao Wu wrote:
> The current implementation of the Erase Block Protocol service
> EraseBlocks() uses the erase command. According to spec eMMC Electrical
> Standard 5.1, Section 6.6.9:
> 
> The erasable unit of the eMMC is the "Erase Group"; Erase group is
> measured in write blocks that are the basic writable units of the Device.
> 
> However, code logic in function EmmcEraseBlocks() does not check whether
> the starting logical block address to be erased and/or the size in bytes
> to be erased is aligned with the erase group. Missing such checks will
> erase the data on additional blocks on an eMMC device.
> 
> This commit will use the Trim command instead to perform the block erase
> for eMMC devices. Unlike the Erase command, according to spec eMMC
> Electrical Standard 5.1, Section 6.6.10:
> 
> The Trim operation is similar to the default erase operation described in
> 6.6.9. The Trim function applies the erase operation to write blocks
> instead of erase groups.
> 
> Also, the Trim operation is mandatory for eMMC devices according to spec
> eMMC Electrical Standard 5.1, Chapter 11, Table 220.
> 
> Cc: Star Zeng<star.zeng@intel.com>
> Cc: Ruiyu Ni<ruiyu.ni@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Hao Wu<hao.a.wu@intel.com>

Reviewed-by: Jun Nie <jun.nie@linaro.org>