soc: rockchip: power-domain: avoid infinite loop

In some cases, we have met the infinite loop in
rockchip_pmu_set_idle_request() or rockchip_do_pmu_set_power_domain().

As the crosbug.com/p/57351 reported, the boot hangs right after this
[1.629163] bootconsole [uart8250] disabled
[1.639286] [drm:drm_core_init] Initialized drm 1.1.0 20060810
[1.645926] [drm:drm_get_platform_dev] Initialized vgem 1.0.0 20120112..
[1.654558] iommu: Adding device ff8f0000.vop to group 0
[1.660569] iommu: Adding device ff900000.vop to group 1
<hang>

This patch adds the error message and timeout to avoid infinite loop if
it fails to get the ack.

Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

diff --git a/drivers/soc/rockchip/pm_domains.c b/drivers/soc/rockchip/pm_domains.c
index 5f106b16e622a5bd7dccf0b4a77f87a2c346011c..988bfd70870623f0f62464bf806c3a583d1cf06d 100644 (file)
--- a/drivers/soc/rockchip/pm_domains.c
+++ b/drivers/soc/rockchip/pm_domains.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/err.h>
 #include <linux/pm_clock.h>
 #include <linux/pm_domain.h>
@@ -105,12 +106,24 @@ static bool rockchip_pmu_domain_is_idle(struct rockchip_pm_domain *pd)
        return (val & pd_info->idle_mask) == pd_info->idle_mask;
 }
 
+static unsigned int rockchip_pmu_read_ack(struct rockchip_pmu *pmu)
+{
+       unsigned int val;
+
+       regmap_read(pmu->regmap, pmu->info->ack_offset, &val);
+       return val;
+}
+
 static int rockchip_pmu_set_idle_request(struct rockchip_pm_domain *pd,
                                         bool idle)
 {
        const struct rockchip_domain_info *pd_info = pd->info;
+       struct generic_pm_domain *genpd = &pd->genpd;
        struct rockchip_pmu *pmu = pd->pmu;
+       unsigned int target_ack;
        unsigned int val;
+       bool is_idle;
+       int ret;
 
        if (pd_info->req_mask == 0)
                return 0;
@@ -120,12 +133,26 @@ static int rockchip_pmu_set_idle_request(struct rockchip_pm_domain *pd,
 
        dsb(sy);
 
-       do {
-               regmap_read(pmu->regmap, pmu->info->ack_offset, &val);
-       } while ((val & pd_info->ack_mask) != (idle ? pd_info->ack_mask : 0));
+       /* Wait util idle_ack = 1 */
+       target_ack = idle ? pd_info->ack_mask : 0;
+       ret = readx_poll_timeout_atomic(rockchip_pmu_read_ack, pmu, val,
+                                       (val & pd_info->ack_mask) == target_ack,
+                                       0, 10000);
+       if (ret) {
+               dev_err(pmu->dev,
+                       "failed to get ack on domain '%s', val=0x%x\n",
+                       genpd->name, val);
+               return ret;
+       }
 
-       while (rockchip_pmu_domain_is_idle(pd) != idle)
-               cpu_relax();
+       ret = readx_poll_timeout_atomic(rockchip_pmu_domain_is_idle, pd,
+                                       is_idle, is_idle == idle, 0, 10000);
+       if (ret) {
+               dev_err(pmu->dev,
+                       "failed to set idle on domain '%s', val=%d\n",
+                       genpd->name, is_idle);
+               return ret;
+       }
 
        return 0;
 }
@@ -198,6 +225,8 @@ static void rockchip_do_pmu_set_power_domain(struct rockchip_pm_domain *pd,
                                             bool on)
 {
        struct rockchip_pmu *pmu = pd->pmu;
+       struct generic_pm_domain *genpd = &pd->genpd;
+       bool is_on;
 
        if (pd->info->pwr_mask == 0)
                return;
@@ -207,8 +236,13 @@ static void rockchip_do_pmu_set_power_domain(struct rockchip_pm_domain *pd,
 
        dsb(sy);
 
-       while (rockchip_pmu_domain_is_on(pd) != on)
-               cpu_relax();
+       if (readx_poll_timeout_atomic(rockchip_pmu_domain_is_on, pd, is_on,
+                                     is_on == on, 0, 10000)) {
+               dev_err(pmu->dev,
+                       "failed to set domain '%s', val=%d\n",
+                       genpd->name, is_on);
+               return;
+       }
 }
 
 static int rockchip_pd_power(struct rockchip_pm_domain *pd, bool power_on)