[PATCH] mmc: mmc_test: align max_seg_size

[PATCH] mmc: mmc_test: align max_seg_size

[Per Forlin]

If max_seg_size is unaligned, mmc_test_map_sg() may create sg element
sizes that are not aligned with 512 byte. Fix, align max_seg_size at
mmc_test_area_init().

Signed-off-by: Per Forlin <per.forlin@stericsson.com>
---
 drivers/mmc/card/mmc_test.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index b038c4a..5848998 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -1581,6 +1581,7 @@ static int mmc_test_area_init(struct mmc_test_card *test, int erase, int fill)
 
 	t->max_segs = test->card->host->max_segs;
 	t->max_seg_sz = test->card->host->max_seg_size;
+	t->max_seg_sz -= t->max_seg_sz % 512;
 
 	t->max_tfr = t->max_sz;
 	if (t->max_tfr >> 9 > test->card->host->max_blk_count)
-- 
1.6.3.3

Re: [PATCH] mmc: mmc_test: align max_seg_size

[Sujit Reddy Thumma]

On 11/14/2011 4:34 PM, Per Forlin wrote:
> If max_seg_size is unaligned, mmc_test_map_sg() may create sg element
> sizes that are not aligned with 512 byte. Fix, align max_seg_size at
> mmc_test_area_init().
>
> Signed-off-by: Per Forlin<per.forlin@stericsson.com>
> ---
>   drivers/mmc/card/mmc_test.c |    1 +
>   1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
> index b038c4a..5848998 100644
> --- a/drivers/mmc/card/mmc_test.c
> +++ b/drivers/mmc/card/mmc_test.c
> @@ -1581,6 +1581,7 @@ static int mmc_test_area_init(struct mmc_test_card *test, int erase, int fill)
>
>   	t->max_segs = test->card->host->max_segs;
>   	t->max_seg_sz = test->card->host->max_seg_size;
> +	t->max_seg_sz -= t->max_seg_sz % 512;

Shouldn't we align this to host->max_blk_size supported by controller? I 
guess there are some extended capacity cards which claim to support 
4096bytes as block size. I am not sure if any card/controller supports 
this mode yet.

>
>   	t->max_tfr = t->max_sz;
>   	if (t->max_tfr>>  9>  test->card->host->max_blk_count)


-- 
Thanks,
Sujit

Re: [PATCH] mmc: mmc_test: align max_seg_size

[Per Förlin]

On 11/17/2011 04:56 AM, Sujit Reddy Thumma wrote:
> On 11/14/2011 4:34 PM, Per Forlin wrote:
>> If max_seg_size is unaligned, mmc_test_map_sg() may create sg element
>> sizes that are not aligned with 512 byte. Fix, align max_seg_size at
>> mmc_test_area_init().
>>
>> Signed-off-by: Per Forlin<per.forlin@stericsson.com>
>> ---
>>   drivers/mmc/card/mmc_test.c |    1 +
>>   1 files changed, 1 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
>> index b038c4a..5848998 100644
>> --- a/drivers/mmc/card/mmc_test.c
>> +++ b/drivers/mmc/card/mmc_test.c
>> @@ -1581,6 +1581,7 @@ static int mmc_test_area_init(struct mmc_test_card *test, int erase, int fill)
>>
>>   	t->max_segs = test->card->host->max_segs;
>>   	t->max_seg_sz = test->card->host->max_seg_size;
>> +	t->max_seg_sz -= t->max_seg_sz % 512;
> 
> Shouldn't we align this to host->max_blk_size supported by controller?
It's up to each test case to set the test transfer size.  It's not necessary to align max_size but it wouldn't make any harm either. All tests use a multiple of 512 blocks, but this may be changed of course in the future to support large blocks.
The max_seg_sz must be aligned otherwise the host driver may get sg-elements that are hard to handle, aligned to 1 byte in the worst case. The test case don't control how the transfer is sg-mapped.

/Per

Re: [PATCH] mmc: mmc_test: align max_seg_size

[Chris Ball]

Hi,

On Mon, Nov 14 2011, Per Forlin wrote:
> If max_seg_size is unaligned, mmc_test_map_sg() may create sg element
> sizes that are not aligned with 512 byte. Fix, align max_seg_size at
> mmc_test_area_init().
>
> Signed-off-by: Per Forlin <per.forlin@stericsson.com>
> ---
>  drivers/mmc/card/mmc_test.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
> index b038c4a..5848998 100644
> --- a/drivers/mmc/card/mmc_test.c
> +++ b/drivers/mmc/card/mmc_test.c
> @@ -1581,6 +1581,7 @@ static int mmc_test_area_init(struct mmc_test_card *test, int erase, int fill)
>  
>  	t->max_segs = test->card->host->max_segs;
>  	t->max_seg_sz = test->card->host->max_seg_size;
> +	t->max_seg_sz -= t->max_seg_sz % 512;
>  
>  	t->max_tfr = t->max_sz;
>  	if (t->max_tfr >> 9 > test->card->host->max_blk_count)

Thanks, pushed to mmc-next for 3.2.  (Sujit, please let us know if you
still have worries about aligning to host->max_blk_size.)

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child

Re: [PATCH] mmc: mmc_test: align max_seg_size

[Sujit Reddy Thumma]

> Hi,
>
> On Mon, Nov 14 2011, Per Forlin wrote:
>> If max_seg_size is unaligned, mmc_test_map_sg() may create sg element
>> sizes that are not aligned with 512 byte. Fix, align max_seg_size at
>> mmc_test_area_init().
>>
>> Signed-off-by: Per Forlin <per.forlin@stericsson.com>
>> ---
>>  drivers/mmc/card/mmc_test.c |    1 +
>>  1 files changed, 1 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
>> index b038c4a..5848998 100644
>> --- a/drivers/mmc/card/mmc_test.c
>> +++ b/drivers/mmc/card/mmc_test.c
>> @@ -1581,6 +1581,7 @@ static int mmc_test_area_init(struct mmc_test_card
>> *test, int erase, int fill)
>>
>>  	t->max_segs = test->card->host->max_segs;
>>  	t->max_seg_sz = test->card->host->max_seg_size;
>> +	t->max_seg_sz -= t->max_seg_sz % 512;
>>
>>  	t->max_tfr = t->max_sz;
>>  	if (t->max_tfr >> 9 > test->card->host->max_blk_count)
>
> Thanks, pushed to mmc-next for 3.2.  (Sujit, please let us know if you
> still have worries about aligning to host->max_blk_size.)

No issues. The change looks good.

-- 
Thanks,
Sujit