From: Dinh Nguyen <dinguyen@kernel.org> To: linux@armlinux.org.uk Cc: dinguyen@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linus.walleij@linaro.org, p.zabel@pengutronix.de, thor.thayer@linux.intel.com Subject: [PATCHv3] ARM: drivers/amba: release and cleanup the resource to allow for deferred probe Date: Wed, 2 Oct 2019 09:35:51 -0500 [thread overview] Message-ID: <20191002143551.32288-1-dinguyen@kernel.org> (raw) With commit "79bdcb202a35 ARM: 8906/1: drivers/amba: add reset control to amba bus probe", the amba bus driver needs to be deferred probe because the reset driver is probed later. However with a deferred probe, the call to request_resource() in the driver returns -EBUSY. The reason is the driver has not released the resource from the previous probe attempt. This patch fixes how we handle the condition of EPROBE_DEFER that is returned from getting the reset controls. For this condition, the patch will jump to defer_probe, which will iounmap, dev_pm_domain_detach, and release the resource. Fixes: 79bdcb202a35 ("ARM: 8906/1: drivers/amba: add reset control to amba bus probe") Signed-off-by: Dinh Nguyen <dinguyen@kernel.org> --- v3: jump to defer_probe where the driver will unmap and pm_detach the driver resource for the next probe attempt v2: release the resource when of_reset_control_array_get_optional_shared() returns EPROBE_DEFER --- drivers/amba/bus.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index f39f075abff9..4a021b1dab3d 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -409,9 +409,12 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent) */ rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node); if (IS_ERR(rstc)) { - if (PTR_ERR(rstc) != -EPROBE_DEFER) + ret = PTR_ERR(rstc); + if (ret == -EPROBE_DEFER) + goto defer_probe; + else dev_err(&dev->dev, "Can't get amba reset!\n"); - return PTR_ERR(rstc); + return ret; } reset_control_deassert(rstc); reset_control_put(rstc); @@ -448,6 +451,7 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent) ret = -ENODEV; } + defer_probe: iounmap(tmp); dev_pm_domain_detach(&dev->dev, true); -- 2.20.0
WARNING: multiple messages have this Message-ID (diff)
From: Dinh Nguyen <dinguyen@kernel.org> To: linux@armlinux.org.uk Cc: thor.thayer@linux.intel.com, linus.walleij@linaro.org, linux-kernel@vger.kernel.org, dinguyen@kernel.org, p.zabel@pengutronix.de, linux-arm-kernel@lists.infradead.org Subject: [PATCHv3] ARM: drivers/amba: release and cleanup the resource to allow for deferred probe Date: Wed, 2 Oct 2019 09:35:51 -0500 [thread overview] Message-ID: <20191002143551.32288-1-dinguyen@kernel.org> (raw) With commit "79bdcb202a35 ARM: 8906/1: drivers/amba: add reset control to amba bus probe", the amba bus driver needs to be deferred probe because the reset driver is probed later. However with a deferred probe, the call to request_resource() in the driver returns -EBUSY. The reason is the driver has not released the resource from the previous probe attempt. This patch fixes how we handle the condition of EPROBE_DEFER that is returned from getting the reset controls. For this condition, the patch will jump to defer_probe, which will iounmap, dev_pm_domain_detach, and release the resource. Fixes: 79bdcb202a35 ("ARM: 8906/1: drivers/amba: add reset control to amba bus probe") Signed-off-by: Dinh Nguyen <dinguyen@kernel.org> --- v3: jump to defer_probe where the driver will unmap and pm_detach the driver resource for the next probe attempt v2: release the resource when of_reset_control_array_get_optional_shared() returns EPROBE_DEFER --- drivers/amba/bus.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index f39f075abff9..4a021b1dab3d 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -409,9 +409,12 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent) */ rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node); if (IS_ERR(rstc)) { - if (PTR_ERR(rstc) != -EPROBE_DEFER) + ret = PTR_ERR(rstc); + if (ret == -EPROBE_DEFER) + goto defer_probe; + else dev_err(&dev->dev, "Can't get amba reset!\n"); - return PTR_ERR(rstc); + return ret; } reset_control_deassert(rstc); reset_control_put(rstc); @@ -448,6 +451,7 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent) ret = -ENODEV; } + defer_probe: iounmap(tmp); dev_pm_domain_detach(&dev->dev, true); -- 2.20.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2019-10-02 14:36 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-10-02 14:35 Dinh Nguyen [this message] 2019-10-02 14:35 ` [PATCHv3] ARM: drivers/amba: release and cleanup the resource to allow for deferred probe Dinh Nguyen 2019-10-02 17:32 ` Russell King - ARM Linux admin 2019-10-02 17:32 ` Russell King - ARM Linux admin 2019-10-02 20:45 ` Dinh Nguyen 2019-10-02 20:45 ` Dinh Nguyen 2019-10-02 20:45 ` Dinh Nguyen 2019-10-02 20:45 ` Dinh Nguyen
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