Re: [PATCH 3/5] tpm: migrate tpm2_probe() to use struct tpm_buf

[J Freyensee <why2jjj.linux@xxxxxxxxx>]

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I'm new to this area of the kernel, but I'm not getting these lines:

> +	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
> +	tpm_buf_destroy(&buf);
>   	if (rc <  0)
Why is this if() check not directly after the tpm_transmit_cmd() call 
that sets rc?  Is it correct you want to destroy buf regardless of the 
tpm_transmit_cmd() outcome?
>   		return rc;
> -
> -	if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
> +	out = (struct tpm_output_header *)buf.data;

So buf has been destroyed, buf.data sill has something valid to assign 
to out?
> +	if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
>   		chip->flags |= TPM_CHIP_FLAG_TPM2;
>   
>   	return 0;
Thanks,
Jay