Re: [PATCH v2 4/7] drm/panfrost: Add support for a second regulator for the GPU

On Wed, Jan 08, 2020 at 01:23:34PM +0800, Nicolas Boichat wrote:

Some GPUs, namely, the bifrost/g72 part on MT8183, have a second regulator for their SRAM, let's add support for that.

• pfdev->regulator_sram = devm_regulator_get_optional(pfdev->dev, "sram");
• if (IS_ERR(pfdev->regulator_sram)) {

This supply is required for the devices that need it so I'd therefore expect the driver to request the supply non-optionally based on the compatible string rather than just hoping that a missing regulator isn't important. Though I do have to wonder given the lack of any active management of the supply if this is *really* part of the GPU or if it's more of a SoC thing, it's not clear what exactly adding this code is achieving.