[PATCH] mmc: meson-gx: set max block count to 256

[PATCH] mmc: meson-gx: set max block count to 256

[Heiner Kallweit]

So far max_blk_count isn't set what results in a default of value 8
to be used (PAGE_SIZE / block size).
Set max_blk_count to 256 as used in the uboot driver.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/mmc/host/meson-gx-mmc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 3308b5b6..030425be 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -799,6 +799,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
 		goto free_host;
 	}
 
+	mmc->max_blk_count = 256;
 	mmc->ops = &meson_mmc_ops;
 	mmc_add_host(mmc);
 
-- 
2.11.0

[PATCH] mmc: meson-gx: set max block count to 256

[Kevin Hilman]

Heiner Kallweit <hkallweit1@gmail.com> writes:

> So far max_blk_count isn't set what results in a default of value 8
> to be used (PAGE_SIZE / block size).
>
> Set max_blk_count to 256 as used in the uboot driver.
>
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>

Thanks for the patch. A minor comment below:

> ---
>  drivers/mmc/host/meson-gx-mmc.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 3308b5b6..030425be 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -799,6 +799,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
>  		goto free_host;
>  	}
>  
> +	mmc->max_blk_count = 256;

A step in the right direction, but the # blocks is actually a 9-bit
field (c.f. length field of cmd_cfg part of descriptor (bits 8:0).

So this should be more like:

	/* blk count is 'length' field of cmd_cfg part of descriptor */
	mmc->max_blk_count = CMD_CFG_LENGTH_MASK + 1;

I tested that change locally, so after changing that, please resend and
feel free to add:

Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>

Kevin

[PATCH] mmc: meson-gx: set max block count to 256

[Heiner Kallweit]

Am 27.01.2017 um 19:28 schrieb Kevin Hilman:
> Heiner Kallweit <hkallweit1@gmail.com> writes:
> 
>> So far max_blk_count isn't set what results in a default of value 8
>> to be used (PAGE_SIZE / block size).
>>
>> Set max_blk_count to 256 as used in the uboot driver.
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> 
> Thanks for the patch. A minor comment below:
> 
>> ---
>>  drivers/mmc/host/meson-gx-mmc.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>> index 3308b5b6..030425be 100644
>> --- a/drivers/mmc/host/meson-gx-mmc.c
>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>> @@ -799,6 +799,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
>>  		goto free_host;
>>  	}
>>  
>> +	mmc->max_blk_count = 256;
> 
> A step in the right direction, but the # blocks is actually a 9-bit
> field (c.f. length field of cmd_cfg part of descriptor (bits 8:0).
> 
> So this should be more like:
> 
> 	/* blk count is 'length' field of cmd_cfg part of descriptor */
> 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK + 1;
> 
> I tested that change locally, so after changing that, please resend and
> feel free to add:
> 
max_blk_count = 0 means unlimited number of blocks. Therefore I think
we have to go with: mmc->max_blk_count = CMD_CFG_LENGTH_MASK
And I figured out later that we also have to set mmc->max_req_size.

In my tests the system never read / wrote more than 8 blocks in a row,
most likely because the upper block layers use 4k blocks.

Therefore setting max_blk_count doesn't really provide a benefit but
I think it's cleaner to expose the actual chip limit.

Rgds, Heiner

> Reviewed-by: Kevin Hilman <khilman@baylibre.com>
> Tested-by: Kevin Hilman <khilman@baylibre.com>
> 
> Kevin
> 

[PATCH] mmc: meson-gx: set max block count to 256

[Kevin Hilman]

Heiner Kallweit <hkallweit1@gmail.com> writes:

> Am 27.01.2017 um 19:28 schrieb Kevin Hilman:
>> Heiner Kallweit <hkallweit1@gmail.com> writes:
>> 
>>> So far max_blk_count isn't set what results in a default of value 8
>>> to be used (PAGE_SIZE / block size).
>>>
>>> Set max_blk_count to 256 as used in the uboot driver.
>>>
>>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>> 
>> Thanks for the patch. A minor comment below:
>> 
>>> ---
>>>  drivers/mmc/host/meson-gx-mmc.c | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>>> index 3308b5b6..030425be 100644
>>> --- a/drivers/mmc/host/meson-gx-mmc.c
>>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>>> @@ -799,6 +799,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
>>>  		goto free_host;
>>>  	}
>>>  
>>> +	mmc->max_blk_count = 256;
>> 
>> A step in the right direction, but the # blocks is actually a 9-bit
>> field (c.f. length field of cmd_cfg part of descriptor (bits 8:0).
>> 
>> So this should be more like:
>> 
>> 	/* blk count is 'length' field of cmd_cfg part of descriptor */
>> 	mmc->max_blk_count = CMD_CFG_LENGTH_MASK + 1;
>> 
>> I tested that change locally, so after changing that, please resend and
>> feel free to add:
>> 
> max_blk_count = 0 means unlimited number of blocks. Therefore I think
> we have to go with: mmc->max_blk_count = CMD_CFG_LENGTH_MASK

Ah, yes.  Good catch.

Kevin

> And I figured out later that we also have to set mmc->max_req_size.
>
> In my tests the system never read / wrote more than 8 blocks in a row,
> most likely because the upper block layers use 4k blocks.
>
> Therefore setting max_blk_count doesn't really provide a benefit but
> I think it's cleaner to expose the actual chip limit.
>
>
>> Reviewed-by: Kevin Hilman <khilman@baylibre.com>
>> Tested-by: Kevin Hilman <khilman@baylibre.com>
>> 
>> Kevin
>>