From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: [PATCH V5 04/14] soc: tegra: pmc: Fix testing of powergate state Date: Thu, 28 Jan 2016 16:33:42 +0000 Message-ID: <1453998832-27383-5-git-send-email-jonathanh@nvidia.com> References: <1453998832-27383-1-git-send-email-jonathanh@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1453998832-27383-1-git-send-email-jonathanh@nvidia.com> Sender: linux-pm-owner@vger.kernel.org To: Stephen Warren , Thierry Reding , Alexandre Courbot , "Rafael J. Wysocki" , Kevin Hilman , Ulf Hansson , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala Cc: linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jon Hunter List-Id: linux-tegra@vger.kernel.org In tegra_powergate_set() the state of the powergates is read and OR'ed with the bit for the powergate of interest. This unsigned 32-bit value is then compared with a boolean value to test if the powergate is already in the desired state. When turning on a powergate, apart from the powergate that is represented by bit 0, this test will always return false and so we may attempt to turn on the powergate when it is already on. After OR'ing the bit for the powergate, check if the result is not equal to zero before comparing with the boolean value. Add a helper function to return the current state of a powergate. Signed-off-by: Jon Hunter --- drivers/soc/tegra/pmc.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c index 1dbdcf06a9ad..99cb2fdd29e1 100644 --- a/drivers/soc/tegra/pmc.c +++ b/drivers/soc/tegra/pmc.c @@ -174,6 +174,11 @@ static void tegra_pmc_writel(u32 value, unsigned long offset) writel(value, pmc->base + offset); } +static inline bool tegra_powergate_state(int id) +{ + return (tegra_pmc_readl(PWRGATE_STATUS) & BIT(id)) != 0; +} + /** * tegra_powergate_set() - set the state of a partition * @id: partition ID @@ -181,13 +186,9 @@ static void tegra_pmc_writel(u32 value, unsigned long offset) */ static int tegra_powergate_set(unsigned int id, bool new_state) { - bool status; - mutex_lock(&pmc->powergates_lock); - status = tegra_pmc_readl(PWRGATE_STATUS) & (1 << id); - - if (status == new_state) { + if (tegra_powergate_state(id) == new_state) { mutex_unlock(&pmc->powergates_lock); return 0; } @@ -230,16 +231,16 @@ EXPORT_SYMBOL(tegra_powergate_power_off); */ int tegra_powergate_is_powered(unsigned int id) { - u32 status; + int status; if (!pmc->soc || id >= pmc->soc->num_powergates) return -EINVAL; mutex_lock(&pmc->powergates_lock); - status = tegra_pmc_readl(PWRGATE_STATUS) & (1 << id); + status = tegra_powergate_state(id); mutex_unlock(&pmc->powergates_lock); - return !!status; + return status; } /** -- 2.1.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: jonathanh@nvidia.com (Jon Hunter) Date: Thu, 28 Jan 2016 16:33:42 +0000 Subject: [PATCH V5 04/14] soc: tegra: pmc: Fix testing of powergate state In-Reply-To: <1453998832-27383-1-git-send-email-jonathanh@nvidia.com> References: <1453998832-27383-1-git-send-email-jonathanh@nvidia.com> Message-ID: <1453998832-27383-5-git-send-email-jonathanh@nvidia.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org In tegra_powergate_set() the state of the powergates is read and OR'ed with the bit for the powergate of interest. This unsigned 32-bit value is then compared with a boolean value to test if the powergate is already in the desired state. When turning on a powergate, apart from the powergate that is represented by bit 0, this test will always return false and so we may attempt to turn on the powergate when it is already on. After OR'ing the bit for the powergate, check if the result is not equal to zero before comparing with the boolean value. Add a helper function to return the current state of a powergate. Signed-off-by: Jon Hunter --- drivers/soc/tegra/pmc.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c index 1dbdcf06a9ad..99cb2fdd29e1 100644 --- a/drivers/soc/tegra/pmc.c +++ b/drivers/soc/tegra/pmc.c @@ -174,6 +174,11 @@ static void tegra_pmc_writel(u32 value, unsigned long offset) writel(value, pmc->base + offset); } +static inline bool tegra_powergate_state(int id) +{ + return (tegra_pmc_readl(PWRGATE_STATUS) & BIT(id)) != 0; +} + /** * tegra_powergate_set() - set the state of a partition * @id: partition ID @@ -181,13 +186,9 @@ static void tegra_pmc_writel(u32 value, unsigned long offset) */ static int tegra_powergate_set(unsigned int id, bool new_state) { - bool status; - mutex_lock(&pmc->powergates_lock); - status = tegra_pmc_readl(PWRGATE_STATUS) & (1 << id); - - if (status == new_state) { + if (tegra_powergate_state(id) == new_state) { mutex_unlock(&pmc->powergates_lock); return 0; } @@ -230,16 +231,16 @@ EXPORT_SYMBOL(tegra_powergate_power_off); */ int tegra_powergate_is_powered(unsigned int id) { - u32 status; + int status; if (!pmc->soc || id >= pmc->soc->num_powergates) return -EINVAL; mutex_lock(&pmc->powergates_lock); - status = tegra_pmc_readl(PWRGATE_STATUS) & (1 << id); + status = tegra_powergate_state(id); mutex_unlock(&pmc->powergates_lock); - return !!status; + return status; } /** -- 2.1.4