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* [PATCH] mmc-utils: Fix scaling of cache size
@ 2020-02-13 22:13 patrick.oppenlander
  2020-02-16  7:18 ` Avri Altman
  0 siblings, 1 reply; 2+ messages in thread
From: patrick.oppenlander @ 2020-02-13 22:13 UTC (permalink / raw)
  To: linux-mmc; +Cc: Patrick Oppenlander

From: Patrick Oppenlander <patrick.oppenlander@gmail.com>

JESD84-B51 7.4.30 CACHE_SIZE [252:249] states that "the size is
indicated as multiple of kilobits". This is also supported by Table 39,
"e.MMC internal sizes and related Units / Granularities" which lists
"32Kb (=4KB)" as the cache size granularity for 4KiB native devices.

Signed-off-by: Patrick Oppenlander <patrick.oppenlander@gmail.com>
---
 mmc_cmds.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mmc_cmds.c b/mmc_cmds.c
index fb37189..a1b1d75 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -1419,8 +1419,8 @@ int do_read_extcsd(int nargs, char **argv)
 		printf("Power off notification [POWER_OFF_LONG_TIME: 0x%02x]\n",
 			ext_csd[247]);
 		printf("Cache Size [CACHE_SIZE] is %d KiB\n",
-			ext_csd[249] << 0 | (ext_csd[250] << 8) |
-			(ext_csd[251] << 16) | (ext_csd[252] << 24));
+			(ext_csd[249] << 0 | (ext_csd[250] << 8) |
+			(ext_csd[251] << 16) | (ext_csd[252] << 24)) / 8);
 	}
 
 	/* A441: Reserved [501:247]
-- 
2.25.0


^ permalink raw reply	[flat|nested] 2+ messages in thread

* RE: [PATCH] mmc-utils: Fix scaling of cache size
  2020-02-13 22:13 [PATCH] mmc-utils: Fix scaling of cache size patrick.oppenlander
@ 2020-02-16  7:18 ` Avri Altman
  0 siblings, 0 replies; 2+ messages in thread
From: Avri Altman @ 2020-02-16  7:18 UTC (permalink / raw)
  To: patrick.oppenlander, linux-mmc

> From: Patrick Oppenlander <patrick.oppenlander@gmail.com>
> 
> JESD84-B51 7.4.30 CACHE_SIZE [252:249] states that "the size is
> indicated as multiple of kilobits". This is also supported by Table 39,
> "e.MMC internal sizes and related Units / Granularities" which lists
> "32Kb (=4KB)" as the cache size granularity for 4KiB native devices.
> 
> Signed-off-by: Patrick Oppenlander <patrick.oppenlander@gmail.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>


> ---
>  mmc_cmds.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mmc_cmds.c b/mmc_cmds.c
> index fb37189..a1b1d75 100644
> --- a/mmc_cmds.c
> +++ b/mmc_cmds.c
> @@ -1419,8 +1419,8 @@ int do_read_extcsd(int nargs, char **argv)
>                 printf("Power off notification [POWER_OFF_LONG_TIME: 0x%02x]\n",
>                         ext_csd[247]);
>                 printf("Cache Size [CACHE_SIZE] is %d KiB\n",
> -                       ext_csd[249] << 0 | (ext_csd[250] << 8) |
> -                       (ext_csd[251] << 16) | (ext_csd[252] << 24));
> +                       (ext_csd[249] << 0 | (ext_csd[250] << 8) |
> +                       (ext_csd[251] << 16) | (ext_csd[252] << 24)) / 8);
>         }
> 
>         /* A441: Reserved [501:247]
> --
> 2.25.0


^ permalink raw reply	[flat|nested] 2+ messages in thread

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2020-02-13 22:13 [PATCH] mmc-utils: Fix scaling of cache size patrick.oppenlander
2020-02-16  7:18 ` Avri Altman

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