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 <[email protected]> --- Changes in v2: - As the Tomasz & Heiko feedback on http://crosreview.com/395589: * Also, need the timeout for rockchip_do_set_power_domain. * s/target_on/is_on, s/target_idle/is_idle. * unsigned int instear of u32. drivers/soc/rockchip/pm_domains.c | 48 +++++++++++++++++++++++++++++++++------ 1 file changed, 41 insertions(+), 7 deletions(-) diff --git a/drivers/soc/rockchip/pm_domains.c b/drivers/soc/rockchip/pm_domains.c index 7acd151..260fbcc 100644 --- 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 val; + unsigned int target_ack; + 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) -- 1.9.1
