On 14 May 2012 15:55, Subhash Jadavani <subhashj@xxxxxxxxxxxxxx> wrote:
> On 5/9/2012 8:18 PM, Saugata Das wrote:
>>
>> From: Saugata Das<saugata.das@xxxxxxxxxx>
>>
>> This patch adds the support for large sector size of 4KB by disabling
>> emulation.
>> This patch passes eMMC DATA_SECTOR_SIZE as the logical block size during
>> mmc_blk_alloc_req.
>>
>> In order to use this patch for 4KB sector size, ensure that
>> USE_NATIVE_SECTOR
>> is enabled, partition table is 4KB sector size aligned and file system
>> block
>> size is 4KB.
>>
>> Signed-off-by: Saugata Das<saugata.das@xxxxxxxxxx>
>> ---
>> drivers/mmc/card/block.c | 6 +++++-
>> drivers/mmc/core/mmc.c | 2 ++
>> 2 files changed, 7 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
>> index a7c75d8..0e54118e 100644
>> --- a/drivers/mmc/card/block.c
>> +++ b/drivers/mmc/card/block.c
>> @@ -1517,7 +1517,11 @@ static struct mmc_blk_data
>> *mmc_blk_alloc_req(struct mmc_card *card,
>> snprintf(md->disk->disk_name, sizeof(md->disk->disk_name),
>> "mmcblk%d%s", md->name_idx, subname ? subname : "");
>>
>> - blk_queue_logical_block_size(md->queue.queue, 512);
>> + if (mmc_card_mmc(card))
>> + blk_queue_logical_block_size(md->queue.queue,
>> + card->ext_csd.data_sector_size);
>
> Shouldn't we also set the physical block size to NATIVE_SECTOR_SIZE value?
>
The physical block size gets set from blk_queue_logical_block_size
> Other question,
> Did you find any eMMC device which 4K native sector size? If yes, please
> share the test results.
>
I have not yet seen the eMMC device implementing 4KB sector. But MMC
vendors are promising this feature, so I prepared this patch. So far,
I have tested by setting "data_sector_size" to 4KB (doing a hack in
mmc_read_ext_csd), configuring file system to have 4KB block size and
mounting it.
> Other than that, this patch looks good to me.
>
> Regards,
> Subhash
>
>> + else
>> + blk_queue_logical_block_size(md->queue.queue, 512);
>> set_capacity(md->disk, size);
>>
>> if (mmc_host_cmd23(card->host)) {
>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>> index 02914d6..8dcbe995 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -533,6 +533,8 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8
>> *ext_csd)
>> } else {
>> card->ext_csd.data_tag_unit_size = 0;
>> }
>> + } else {
>> + card->ext_csd.data_sector_size = 512;
>> }
>>
>> out:
>
>
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