Re: [PATCH] arm64: dts: imx8mq: disable DDRC node by default
From: Lucas Stach <dev@lynxeye.de>
Date: 2021-12-13 15:07:33
Am Sonntag, dem 12.12.2021 um 16:29 -0300 schrieb Fabio Estevam:
Hi Lucas, On Sun, Dec 12, 2021 at 4:16 PM Lucas Stach [off-list ref] wrote:quoted
Without a OPP table or a downstream TF-A running on the system the DDRC will fail to probe, as it has no means to scale the DRAM frequency in that case. This however will block the bus scaling driver to come up and this in turn prevents other devices that hook into the interconnect from probing. If the DDRC is disabled, the interconnect driver will simply ignore it. As most systems don't want to scale the DRAM frequency, disable the node by default and only enable it on the systems that actually uses this capability and provides a valid OPP table in the DT. Signed-off-by: Lucas Stach <dev@lynxeye.de>Reviewed-by: Fabio Estevam <festevam@gmail.com> Should we do the same on imx8mm too?
Not sure, with the i.MX8MM there are a lot more systems that are providing a valid OPP table. Also I don't see the interconnect being hooked up to devices in the i.MX8MM DT, so a non-function interconnect driver, will at least not block other devices as is the case with the i.MX8MQ. However, there still is the issue that all those systems those depend on a downstream TF-A running on the system, as upstream TF-A has no support for scaling the DDR frequency. Regards, Lucas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel