Re: [PATCH v4 2/7] drm/panel: himax-hx83102: Break out as separate driver

From: Doug Anderson
Date: Tue May 07 2024 - 20:04:22 EST


Hi,

On Tue, May 7, 2024 at 6:53 AM Cong Yang
<yangcong5@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> +static int hx83102_enable_extended_cmds(struct hx83102 *ctx, bool enable)
> +{
> + struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
> +
> + if (enable)
> + mipi_dsi_dcs_write_seq_multi(&dsi_ctx, HX83102_SETEXTC, 0x83, 0x10, 0x21, 0x55, 0x00);
> + else
> + mipi_dsi_dcs_write_seq_multi(&dsi_ctx, HX83102_SETEXTC, 0x00, 0x00, 0x00);
> +
> + return 0;

You're throwing away the error codes returned by the
mipi_dsi_dcs_write_seq_multi(), which you shouldn't do. You have two
options:

Option #1: return dsi_ctx.accum_err here and then check the return
value in callers.

Option #2: instead of having this function take "struct hx83102 *ctx",
just have it take "struct mipi_dsi_multi_context *dsi_ctx". Then it
can return void and everything will be fine.

I'd prefer option #2 but either is OK w/ me.


> +static int starry_himax83102_j02_init(struct hx83102 *ctx)
> +{
> + struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
> +
> + hx83102_enable_extended_cmds(ctx, true);
> + mipi_dsi_dcs_write_seq_multi(&dsi_ctx, HX83102_SETPOWER, 0x2c, 0xb5, 0xb5, 0x31, 0xf1,
> + 0x31, 0xd7, 0x2f, 0x36, 0x36, 0x36, 0x36, 0x1a, 0x8b, 0x11,
> + 0x65, 0x00, 0x88, 0xfa, 0xff, 0xff, 0x8f, 0xff, 0x08, 0x74,
> + 0x33);

The indentation is still off here. You have 5 tabs followed by a
space. To make things line up with the opening brace I think it should
be 4 tabs followed by 5 spaces.


> +static int hx83102_enable(struct drm_panel *panel)
> +{
> + struct hx83102 *ctx = panel_to_hx83102(panel);
> + struct mipi_dsi_device *dsi = ctx->dsi;
> + struct device *dev = &dsi->dev;
> + int ret;
> +
> + ret = ctx->desc->init(ctx);
> + if (ret)
> + return ret;

You're still changing behavior here. In the old boe-tv101wum-nl6
driver the init() function was invoked at the end of prepare(). Now
you've got it at the beginning of enable(). If this change is
important it should be in a separate commit and explained.


> + ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
> + if (ret) {
> + dev_err(dev, "Failed to exit sleep mode: %d\n", ret);
> + return ret;
> + }
> +
> + msleep(120);
> +
> + ret = mipi_dsi_dcs_set_display_on(dsi);
> + if (ret) {
> + dev_err(dev, "Failed to turn on the display: %d\n", ret);
> + }

The old boe-tv101wum-nl6 driver didn't call
mipi_dsi_dcs_exit_sleep_mode() nor mipi_dsi_dcs_set_display_on() in
its enable routine, did it? If this change is important please put it
in a separate change and justify it.


-Doug