Bootloader enabled display, when the driver is built-in (rather than a module loaded after CCF/genpd disable "unused" clocks/powerdomains) causes problems since the driver thinks the clocks are off, but in fact they are on. This causes (for example) clk_set_rate() to fail.

A better solution would be to support display handover from bootloader, but that will require some CCF+genpd changes before that is possible. So until then, we need this workaround.

Signed-off-by: Rob Clark robdclark@gmail.com --- drivers/gpu/drm/msm/dsi/dsi_host.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 0f7324a686ca..589818d027e4 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -418,6 +418,40 @@ static int dsi_clk_init(struct msm_dsi_host *msm_host) __func__, ret); } } + + /* + * If the bootloader enables the display, and the driver is + * built-in (as opposed to module, loaded after clk/genpd + * framework disables "unused" clocks and power domains, we + * would already have clocks enabled. But kms thinks that + * everything is disabled. This causes problems, for ex, + * when trying to clk_set_rate() on bootloader enabled + * clocks. + * + * Work around this for now, until we have a better solution + * in place, by doing an extra enable/disable. This forces + * things to a disabled state. + */ + if (cfg_hnd->major == MSM_DSI_VER_MAJOR_6G) { + clk_prepare_enable(msm_host->byte_clk); + clk_prepare_enable(msm_host->pixel_clk); + clk_prepare_enable(msm_host->esc_clk); + + clk_disable_unprepare(msm_host->esc_clk); + clk_disable_unprepare(msm_host->pixel_clk); + clk_disable_unprepare(msm_host->byte_clk); + } else { + clk_prepare_enable(msm_host->byte_clk); + clk_prepare_enable(msm_host->esc_clk); + clk_prepare_enable(msm_host->src_clk); + clk_prepare_enable(msm_host->pixel_clk); + + clk_disable_unprepare(msm_host->pixel_clk); + clk_disable_unprepare(msm_host->src_clk); + clk_disable_unprepare(msm_host->esc_clk); + clk_disable_unprepare(msm_host->byte_clk); + } + exit: return ret; }