On 4/1/20 3:05 PM, Heinrich Schuchardt wrote:
> On 4/1/20 5:04 AM, Jaehoon Chung wrote:
>> Hi,
>>
>> On 3/30/20 2:24 PM, Heinrich Schuchardt wrote:
>>> Boot partitions of eMMC devices can be power on or permanently write
>>> protected. Let the 'mmc info' command display the protection state.
>>>
>>> Signed-off-by: Heinrich Schuchardt <xypron.g...@gmx.de>
>>> ---
>>> cmd/mmc.c | 24 ++++++++++++++++++++++++
>>> 1 file changed, 24 insertions(+)
>>>
>>> diff --git a/cmd/mmc.c b/cmd/mmc.c
>>> index 6f3cb85cc0..d62c85e439 100644
>>> --- a/cmd/mmc.c
>>> +++ b/cmd/mmc.c
>>> @@ -54,6 +54,8 @@ static void print_mmcinfo(struct mmc *mmc)
>>> if (!IS_SD(mmc) && mmc->version >= MMC_VERSION_4_41) {
>>> bool has_enh = (mmc->part_support & ENHNCD_SUPPORT) != 0;
>>> bool usr_enh = has_enh && (mmc->part_attr & EXT_CSD_ENH_USR);
>>> + u8 wp, ext_csd[MMC_MAX_BLOCK_LEN];
>>> + int ret;
>>>
>>> #if CONFIG_IS_ENABLED(MMC_HW_PARTITIONING)
>>> puts("HC WP Group Size: ");
>>> @@ -90,6 +92,28 @@ static void print_mmcinfo(struct mmc *mmc)
>>> putc('\n');
>>> }
>>> }
>>> + ret = mmc_send_ext_csd(mmc, ext_csd);
>>> + if (ret)
>>> + return;
>>
>> Is it really needed to call mmc_send_ext_csd() at here.
>> ext_csd register value was already read somewhere.
>
> struct mmc does not contain the extended CSD. Performancewise it does
> not make sense to carry a copy which would have to be updated after each
> command that could potentially update it like SWITCH.
Why doesn't make sense to carry a copy? Its value can be updated whenever it's
changed.
If someone want to set "write protect", then it has to follow sequence.
read ext_csd -> check value -> send_switch command
Then it's possible to keep its value..
And some values are one-time programmable. it's not efficient about sending
command to read again.
Best Regards,
Jaehoon Chung
>
> The call to mmc_send_ext_csd() does not lead to any visible performance
> issue here.
>
> Best regards
>
> Heinrich
>
>>
>> Best Regards,
>> Jaehoon Chung
>>
>>> + wp = ext_csd[EXT_CSD_BOOT_WP_STATUS];
>>> + for (i = 0; i < 2; ++i) {
>>> + printf("Boot area %d is ", i);
>>> + switch (wp & 3) {
>>> + case 0:
>>> + printf("not write protected\n");
>>> + break;
>>> + case 1:
>>> + printf("power on protected\n");
>>> + break;
>>> + case 2:
>>> + printf("permanently protected\n");
>>> + break;
>>> + default:
>>> + printf("in reserved protection state\n");
>>> + break;
>>> + }
>>> + wp >>= 2;
>>> + }
>>> }
>>> }
>>> static struct mmc *init_mmc_device(int dev, bool force_init)
>>> --
>>> 2.25.1
>>>
>>>
>>>
>>
>
>
>
