On 20/07/23 11:38, Wenchao Chen wrote:
> On Thu, Jul 20, 2023 at 2:45 PM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>>
>> On 19/07/23 05:46, Wenchao Chen wrote:
>>> On Tue, Jul 18, 2023 at 2:13 PM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>>>>
>>>> On 18/07/23 04:15, Wenchao Chen wrote:
>>>>> When the card is reset, mmc_card_init() will check if this
>>>>> card is the previous card by comparing the CID.
>>>>>
>>>>> If the firmware is upgraded, the product version may change,
>>>>> so we remove the product version from the CID check.
>>>>
>>>> What is the use-case for this? I would have thought it is safer
>>>> not to assume anything about the card after the firmware has been
>>>> upgraded.
>>>>
>>> Hi adrian
>>> Understood, but we have case:
>>> 1.Before the firmware upgrade
>>> [T5745@C0] mmc0 oldcard raw->cid[2]: 32691160, raw->cid[3]: d9241800
>>> PRV=69
>>> 2.After the firmware upgrade
>>> [T5745@C0] mmc0 cid[2]: 32011160 cid[3]: d9241800
>>> PRV=01
>>> If the PRV is not excluded in the CID check, then the mmc
>>> initialization will fail after the mmc reset.
>>> In addition, CRC is excluded because some controllers support
>>> SDHCI_QUIRK2_RSP_136_HAS_CRC.
>>
>> I do not know what others are doing in this regard, nor what
>> circumstances are leading to the re-initialization.
>>
> There is a way: reboot the machine, but we don't want to do that.
>
> When the firmware is upgraded, we need to complete the firmware
> update by reset card, and the card will be initialized by mmc_init_card
> after mmc reset.
>
>> Presumably a clean re-initialization could be done by
>> unbinding and rebinding the host controller.
>>
> Could you tell me how to do that?
> Thanks.
It depends on the name of the device and where the host
controller driver is in sysfs, but here is an example for
sdhci-pci with eMMC:
# ls /sys/bus/pci/drivers/sdhci-pci/
0000:00:1a.0/ new_id uevent
bind remove_id unbind
# echo "0000:00:1a.0" > /sys/bus/pci/drivers/sdhci-pci/unbind
[ 484.853761] mmc0: card 0001 removed
# echo "0000:00:1a.0" > /sys/bus/pci/drivers/sdhci-pci/bind
[ 490.621524] sdhci-pci 0000:00:1a.0: SDHCI controller found [8086:4b47] (rev 11)
[ 490.638520] mmc0: CQHCI version 5.10
[ 490.643630] mmc0: SDHCI controller on PCI [0000:00:1a.0] using ADMA 64-bit
[ 490.651837] sdhci-pci 0000:00:1a.1: SDHCI controller found [8086:4b48] (rev 11)
[ 490.780139] mmc0: Command Queue Engine enabled
[ 490.785132] mmc0: new HS400 MMC card at address 0001
[ 490.791171] mmcblk0: mmc0:0001 S0J57X 29.6 GiB
[ 490.796320] mmcblk0boot0: mmc0:0001 S0J57X partition 1 31.5 MiB
[ 490.803121] mmcblk0boot1: mmc0:0001 S0J57X partition 2 31.5 MiB
[ 490.809918] mmcblk0rpmb: mmc0:0001 S0J57X partition 3 4.00 MiB, chardev (240:0)
[ 490.821390] sdhci-pci 0000:00:1a.1: SDHCI controller found [8086:4b48] (rev 11)
>
>>>
>>>>>
>>>>> Signed-off-by: Wenchao Chen <wenchao.chen@xxxxxxxxxx>
>>>>> ---
>>>>> drivers/mmc/core/mmc.c | 18 +++++++++++++++++-
>>>>> 1 file changed, 17 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>>>>> index 89cd48fcec79..32a73378d5c3 100644
>>>>> --- a/drivers/mmc/core/mmc.c
>>>>> +++ b/drivers/mmc/core/mmc.c
>>>>> @@ -32,6 +32,9 @@
>>>>> #define MIN_CACHE_EN_TIMEOUT_MS 1600
>>>>> #define CACHE_FLUSH_TIMEOUT_MS 30000 /* 30s */
>>>>>
>>>>> +#define MMC_CID_PRV_MASK GENMASK(23, 16)
>>>>> +#define MMC_CID_CRC_MASK GENMASK(7, 0)
>>>>> +
>>>>> static const unsigned int tran_exp[] = {
>>>>> 10000, 100000, 1000000, 10000000,
>>>>> 0, 0, 0, 0
>>>>> @@ -126,6 +129,19 @@ static int mmc_decode_cid(struct mmc_card *card)
>>>>> return 0;
>>>>> }
>>>>>
>>>>> +static int mmc_check_cid(u32 *cid, u32 *raw_cid)
>>>>> +{
>>>>> + /*
>>>>> + * When comparing CID, we need to remove the product
>>>>> + * version (Field PRV, offset 55:48) and CRC. Because
>>>>> + * the product version will change when the firmware
>>>>> + * is upgraded. Also, the new CRC is different.
>>>>> + */
>>>>> + return cid[0] != raw_cid[0] || cid[1] != raw_cid[1] ||
>>>>> + (cid[2] & ~MMC_CID_PRV_MASK) != (raw_cid[2] & ~MMC_CID_PRV_MASK) ||
>>>>> + (cid[3] & ~MMC_CID_CRC_MASK) != (raw_cid[3] & ~MMC_CID_CRC_MASK);
>>>>> +}
>>>>> +
>>>>> static void mmc_set_erase_size(struct mmc_card *card)
>>>>> {
>>>>> if (card->ext_csd.erase_group_def & 1)
>>>>> @@ -1640,7 +1656,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>>>>> goto err;
>>>>>
>>>>> if (oldcard) {
>>>>> - if (memcmp(cid, oldcard->raw_cid, sizeof(cid)) != 0) {
>>>>> + if (mmc_check_cid(cid, oldcard->raw_cid)) {
>>>>> pr_debug("%s: Perhaps the card was replaced\n",
>>>>> mmc_hostname(host));
>>>>> err = -ENOENT;
>>>>
>>
