Re: [PATCH v2 2/5] i3c: mipi-i3c-hci: Add a quirk to set PIO mode

From: Jarkko Nikula
Date: Tue Aug 06 2024 - 03:09:39 EST


On 8/5/24 12:26 PM, Shyam Sundar S K wrote:
Hi,

On 8/2/2024 19:28, Jarkko Nikula wrote:

This is true, I see this now from pre-v1.0, v1.0. v1.1 and v1.2 specs
too, HC_CONTROL_PIO_MODE bit is present only after v1.0. And therefore
version != HCI_VERSION_V1 check is not fully correct since bit is not
present in pre-v1.0 HW versions either.


Agreed. HC_CONTROL_PIO_MODE is only present in v1.1 and v1.2.

anything below v1.0, the version check handling is already present;

switch (regval & ~0xf) {
case 0x100: /* version 1.0 */
case 0x110: /* version 1.1 */
case 0x200: /* version 2.0 */
break;
default:
dev_err(&hci->master.dev, "unsupported HCI version\n");
return -EPROTONOSUPPORT;
}

Let me know your thoughts.

Yeah, true. I'd still use version > v1.0 check because that reflects the current situation. Mostly to avoid confusion when reading the code but also if someone adds support for pre-v1.0 HW (perhaps unlikely) and then doesn't need to change version check here.