Am 17. Februar 2017 06:11:53 MEZ schrieb Christophe Ricard 
<christophe.ric...@gmail.com>:
>I am not sure i understand here, are you considering there could be 
>burstcount > 64 with "TCG" TPM ?
>
With the current upstream version, any command larger with a response of more 
than 64 byte is broken, since the splitting loop went missing during the merge.
At least with our tpms that's the case.
(I think we are signalling a higher burstcount value than 64, which is allowed)

>Or is this because of TIS vs PTP differences ?
>
>To be honest, this is a little behind me now :-)
>
>
>On 16/02/2017 08:08, Peter Huewe wrote:
>> Limiting transfers to MAX_SPI_FRAMESIZE was not expected by the upper
>> layers, as tpm_tis has no such limitation. Add a loop to hide that
>> limitation.
>>
>> Cc: <sta...@vger.kernel.org>
>> Fixes: 0edbfea537d1 ("tpm/tpm_tis_spi: Add support for spi phy")
>> Signed-off-by: Alexander Steffen <alexander.stef...@infineon.com>
>> Signed-off-by: Peter Huewe <peter.hu...@infineon.com>
>> ---
>>   drivers/char/tpm/tpm_tis_spi.c | 108
>++++++++++++++++++++++-------------------
>>   1 file changed, 57 insertions(+), 51 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_tis_spi.c
>b/drivers/char/tpm/tpm_tis_spi.c
>> index 16938e2253d2..b50c5b072df3 100644
>> --- a/drivers/char/tpm/tpm_tis_spi.c
>> +++ b/drivers/char/tpm/tpm_tis_spi.c
>> @@ -61,68 +61,74 @@ static int tpm_tis_spi_transfer(struct
>tpm_tis_data *data, u32 addr, u8 len,
>>   {
>>      struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
>>      int ret;
>> -    struct spi_message m;
>> -    struct spi_transfer spi_xfer = {
>> -            .tx_buf = phy->tx_buf,
>> -            .rx_buf = phy->rx_buf,
>> -            .len = 4,
>> -            .cs_change = 1,
>> -    };
>> -
>> -    if (len > MAX_SPI_FRAMESIZE)
>> -            return -ENOMEM;
>>   
>> -    phy->tx_buf[0] = direction | (len - 1);
>> -    phy->tx_buf[1] = 0xd4;
>> -    phy->tx_buf[2] = addr >> 8;
>> -    phy->tx_buf[3] = addr;
>> +    spi_bus_lock(phy->spi_device->master);
>>   
>> -    spi_message_init(&m);
>> -    spi_message_add_tail(&spi_xfer, &m);
>> +    while (len) {
>> +            struct spi_message m;
>> +            struct spi_transfer spi_xfer = {
>> +                    .tx_buf = phy->tx_buf,
>> +                    .rx_buf = phy->rx_buf,
>> +                    .len = 4,
>> +                    .cs_change = 1,
>> +            };
>> +            u8 transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE);
>> +
>> +            phy->tx_buf[0] = direction | (transfer_len - 1);
>> +            phy->tx_buf[1] = 0xd4;
>> +            phy->tx_buf[2] = addr >> 8;
>> +            phy->tx_buf[3] = addr;
>> +
>> +            spi_message_init(&m);
>> +            spi_message_add_tail(&spi_xfer, &m);
>> +            ret = spi_sync_locked(phy->spi_device, &m);
>> +            if (ret < 0)
>> +                    goto exit;
>>   
>> -    spi_bus_lock(phy->spi_device->master);
>> -    ret = spi_sync_locked(phy->spi_device, &m);
>> -    if (ret < 0)
>> -            goto exit;
>> -
>> -    if ((phy->rx_buf[3] & 0x01) == 0) {
>> -            // handle SPI wait states
>> -            int i;
>> -
>> -            phy->tx_buf[0] = 0;
>> -
>> -            for (i = 0; i < TPM_RETRY; i++) {
>> -                    spi_xfer.len = 1;
>> -                    spi_message_init(&m);
>> -                    spi_message_add_tail(&spi_xfer, &m);
>> -                    ret = spi_sync_locked(phy->spi_device, &m);
>> -                    if (ret < 0)
>> +            if ((phy->rx_buf[3] & 0x01) == 0) {
>> +                    // handle SPI wait states
>> +                    int i;
>> +
>> +                    phy->tx_buf[0] = 0;
>> +
>> +                    for (i = 0; i < TPM_RETRY; i++) {
>> +                            spi_xfer.len = 1;
>> +                            spi_message_init(&m);
>> +                            spi_message_add_tail(&spi_xfer, &m);
>> +                            ret = spi_sync_locked(phy->spi_device, &m);
>> +                            if (ret < 0)
>> +                                    goto exit;
>> +                            if (phy->rx_buf[0] & 0x01)
>> +                                    break;
>> +                    }
>> +
>> +                    if (i == TPM_RETRY) {
>> +                            ret = -ETIMEDOUT;
>>                              goto exit;
>> -                    if (phy->rx_buf[0] & 0x01)
>> -                            break;
>> +                    }
>>              }
>>   
>> -            if (i == TPM_RETRY) {
>> -                    ret = -ETIMEDOUT;
>> -                    goto exit;
>> +            spi_xfer.cs_change = 0;
>> +            spi_xfer.len = transfer_len;
>> +
>> +            if (direction) {
>> +                    spi_xfer.tx_buf = NULL;
>> +                    spi_xfer.rx_buf = buffer;
>> +            } else {
>> +                    spi_xfer.tx_buf = buffer;
>> +                    spi_xfer.rx_buf = NULL;
>>              }
>> -    }
>>   
>> -    spi_xfer.cs_change = 0;
>> -    spi_xfer.len = len;
>> +            spi_message_init(&m);
>> +            spi_message_add_tail(&spi_xfer, &m);
>> +            ret = spi_sync_locked(phy->spi_device, &m);
>> +            if (ret < 0)
>> +                    goto exit;
>>   
>> -    if (direction) {
>> -            spi_xfer.tx_buf = NULL;
>> -            spi_xfer.rx_buf = buffer;
>> -    } else {
>> -            spi_xfer.tx_buf = buffer;
>> -            spi_xfer.rx_buf = NULL;
>> +            len -= transfer_len;
>> +            buffer += transfer_len;
>>      }
>>   
>> -    spi_message_init(&m);
>> -    spi_message_add_tail(&spi_xfer, &m);
>> -    ret = spi_sync_locked(phy->spi_device, &m);
>> -
>>   exit:
>>      spi_bus_unlock(phy->spi_device->master);
>>      return ret;

-- 
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