soc: imx: gpc: Use GENPD_FLAG_RPM_ALWAYS_ON for ERR009619

This allows PU domain to be turned off in suspend and save power.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c
index 7d14a4b4e82a..29b43651c261 100644
--- a/drivers/soc/imx/gpc.c
+++ b/drivers/soc/imx/gpc.c
@@ -431,10 +431,19 @@ static int imx_gpc_probe(struct platform_device *pdev)
                 return ret;
         }
 
-        /* Disable PU power down in normal operation if ERR009619 is present */
+        /*
+         * Disable PU power down by runtime PM if ERR009619 is present.
+         *
+         * The PRE clock will be paused for several cycles when turning on the
+         * PU domain LDO from power down state. If PRE is in use at that time,
+         * the IPU/PRG cannot get the correct display data from the PRE.
+         *
+         * This is not a concern when the whole system enters suspend state, so
+         * it's safe to power down PU in this case.
+         */
         if (of_id_data->err009619_present)
                 imx_gpc_domains[GPC_PGC_DOMAIN_PU].base.flags |=
-                                GENPD_FLAG_ALWAYS_ON;
+                                GENPD_FLAG_RPM_ALWAYS_ON;
 
         /* Keep DISP always on if ERR006287 is present */
         if (of_id_data->err006287_present)