4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Laurent Pinchart laurent.pinchart@ideasonboard.com
[ Upstream commit 215003b4ae1d47035092fef73b6a22aa82037091 ]
There's no reason to delay initialization of most of the driver (such as mapping memory I/O, getting clocks or enabling runtime PM) to the component master bind handler.
This additionally fixes a real PM issue caused enabling runtime PM in the bind handler.
The bind handler performs the following sequence of PM operations:
pm_runtime_enable(dev); pm_runtime_get_sync(dev);
... (access the hardware to read the device revision) ...
pm_runtime_put_sync(dev);
If a failure occurs at this point, the error path calls pm_runtime_disable() to balance the pm_runtime_enable() call.
To understand the problem, it should be noted that the bind handler is called when one of the component registers itself, which happens in the component's probe handler. Furthermore, as the components are children of the DSS, the device core calls pm_runtime_get_sync() on the DSS platform device before calling the component's probe handler. This increases the DSS power usage count but doesn't runtime resume the device, as runtime PM is disabled at that point.
The bind handler is thus called with runtime PM disabled, with the device runtime suspended, but with the power usage count larger than 0. The pm_runtime_get_sync() call will thus further increase the power usage count and runtime resume the device. The pm_runtime_put_sync() handler will decrease the power usage count to a non-zero value and will thus not suspend the device. Finally, the pm_runtime_disable() call will disable runtime PM, preventing the pm_runtime_put() call in the device core from runtime suspending the device. The DSS device is thus left powered on.
To fix this, move the initialization code from the bind handler to the probe handler.
Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Reviewed-by: Sebastian Reichel sebastian.reichel@collabora.co.uk Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/omapdrm/dss/dss.c | 193 ++++++++++++++++++++------------------ 1 file changed, 104 insertions(+), 89 deletions(-)
--- a/drivers/gpu/drm/omapdrm/dss/dss.c +++ b/drivers/gpu/drm/omapdrm/dss/dss.c @@ -1299,88 +1299,18 @@ static const struct soc_device_attribute
static int dss_bind(struct device *dev) { - struct platform_device *pdev = to_platform_device(dev); - struct resource *dss_mem; - u32 rev; int r;
- dss_mem = platform_get_resource(dss.pdev, IORESOURCE_MEM, 0); - dss.base = devm_ioremap_resource(&pdev->dev, dss_mem); - if (IS_ERR(dss.base)) - return PTR_ERR(dss.base); - - r = dss_get_clocks(); + r = component_bind_all(dev, NULL); if (r) return r;
- r = dss_setup_default_clock(); - if (r) - goto err_setup_clocks; - - r = dss_video_pll_probe(pdev); - if (r) - goto err_pll_init; - - r = dss_init_ports(pdev); - if (r) - goto err_init_ports; - - pm_runtime_enable(&pdev->dev); - - r = dss_runtime_get(); - if (r) - goto err_runtime_get; - - dss.dss_clk_rate = clk_get_rate(dss.dss_clk); - - /* Select DPLL */ - REG_FLD_MOD(DSS_CONTROL, 0, 0, 0); - - dss_select_dispc_clk_source(DSS_CLK_SRC_FCK); - -#ifdef CONFIG_OMAP2_DSS_VENC - REG_FLD_MOD(DSS_CONTROL, 1, 4, 4); /* venc dac demen */ - REG_FLD_MOD(DSS_CONTROL, 1, 3, 3); /* venc clock 4x enable */ - REG_FLD_MOD(DSS_CONTROL, 0, 2, 2); /* venc clock mode = normal */ -#endif - dss.dsi_clk_source[0] = DSS_CLK_SRC_FCK; - dss.dsi_clk_source[1] = DSS_CLK_SRC_FCK; - dss.dispc_clk_source = DSS_CLK_SRC_FCK; - dss.lcd_clk_source[0] = DSS_CLK_SRC_FCK; - dss.lcd_clk_source[1] = DSS_CLK_SRC_FCK; - - rev = dss_read_reg(DSS_REVISION); - pr_info("OMAP DSS rev %d.%d\n", FLD_GET(rev, 7, 4), FLD_GET(rev, 3, 0)); - - dss_runtime_put(); - - r = component_bind_all(&pdev->dev, NULL); - if (r) - goto err_component; - - dss_debugfs_create_file("dss", dss_dump_regs); - pm_set_vt_switch(0);
omapdss_gather_components(dev); omapdss_set_is_initialized(true);
return 0; - -err_component: -err_runtime_get: - pm_runtime_disable(&pdev->dev); - dss_uninit_ports(pdev); -err_init_ports: - if (dss.video1_pll) - dss_video_pll_uninit(dss.video1_pll); - - if (dss.video2_pll) - dss_video_pll_uninit(dss.video2_pll); -err_pll_init: -err_setup_clocks: - dss_put_clocks(); - return r; }
static void dss_unbind(struct device *dev) @@ -1390,18 +1320,6 @@ static void dss_unbind(struct device *de omapdss_set_is_initialized(false);
component_unbind_all(&pdev->dev, NULL); - - if (dss.video1_pll) - dss_video_pll_uninit(dss.video1_pll); - - if (dss.video2_pll) - dss_video_pll_uninit(dss.video2_pll); - - dss_uninit_ports(pdev); - - pm_runtime_disable(&pdev->dev); - - dss_put_clocks(); }
static const struct component_master_ops dss_component_ops = { @@ -1433,10 +1351,46 @@ static int dss_add_child_component(struc return 0; }
+static int dss_probe_hardware(void) +{ + u32 rev; + int r; + + r = dss_runtime_get(); + if (r) + return r; + + dss.dss_clk_rate = clk_get_rate(dss.dss_clk); + + /* Select DPLL */ + REG_FLD_MOD(DSS_CONTROL, 0, 0, 0); + + dss_select_dispc_clk_source(DSS_CLK_SRC_FCK); + +#ifdef CONFIG_OMAP2_DSS_VENC + REG_FLD_MOD(DSS_CONTROL, 1, 4, 4); /* venc dac demen */ + REG_FLD_MOD(DSS_CONTROL, 1, 3, 3); /* venc clock 4x enable */ + REG_FLD_MOD(DSS_CONTROL, 0, 2, 2); /* venc clock mode = normal */ +#endif + dss.dsi_clk_source[0] = DSS_CLK_SRC_FCK; + dss.dsi_clk_source[1] = DSS_CLK_SRC_FCK; + dss.dispc_clk_source = DSS_CLK_SRC_FCK; + dss.lcd_clk_source[0] = DSS_CLK_SRC_FCK; + dss.lcd_clk_source[1] = DSS_CLK_SRC_FCK; + + rev = dss_read_reg(DSS_REVISION); + pr_info("OMAP DSS rev %d.%d\n", FLD_GET(rev, 7, 4), FLD_GET(rev, 3, 0)); + + dss_runtime_put(); + + return 0; +} + static int dss_probe(struct platform_device *pdev) { const struct soc_device_attribute *soc; struct component_match *match = NULL; + struct resource *dss_mem; int r;
dss.pdev = pdev; @@ -1451,20 +1405,69 @@ static int dss_probe(struct platform_dev else dss.feat = of_match_device(dss_of_match, &pdev->dev)->data;
- r = dss_initialize_debugfs(); + /* Map I/O registers, get and setup clocks. */ + dss_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dss.base = devm_ioremap_resource(&pdev->dev, dss_mem); + if (IS_ERR(dss.base)) + return PTR_ERR(dss.base); + + r = dss_get_clocks(); if (r) return r;
- /* add all the child devices as components */ + r = dss_setup_default_clock(); + if (r) + goto err_put_clocks; + + /* Setup the video PLLs and the DPI and SDI ports. */ + r = dss_video_pll_probe(pdev); + if (r) + goto err_put_clocks; + + r = dss_init_ports(pdev); + if (r) + goto err_uninit_plls; + + /* Enable runtime PM and probe the hardware. */ + pm_runtime_enable(&pdev->dev); + + r = dss_probe_hardware(); + if (r) + goto err_pm_runtime_disable; + + /* Initialize debugfs. */ + r = dss_initialize_debugfs(); + if (r) + goto err_pm_runtime_disable; + + dss_debugfs_create_file("dss", dss_dump_regs); + + /* Add all the child devices as components. */ device_for_each_child(&pdev->dev, &match, dss_add_child_component);
r = component_master_add_with_match(&pdev->dev, &dss_component_ops, match); - if (r) { - dss_uninitialize_debugfs(); - return r; - } + if (r) + goto err_uninit_debugfs;
return 0; + +err_uninit_debugfs: + dss_uninitialize_debugfs(); + +err_pm_runtime_disable: + pm_runtime_disable(&pdev->dev); + dss_uninit_ports(pdev); + +err_uninit_plls: + if (dss.video1_pll) + dss_video_pll_uninit(dss.video1_pll); + if (dss.video2_pll) + dss_video_pll_uninit(dss.video2_pll); + +err_put_clocks: + dss_put_clocks(); + + return r; }
static int dss_remove(struct platform_device *pdev) @@ -1473,6 +1476,18 @@ static int dss_remove(struct platform_de
dss_uninitialize_debugfs();
+ pm_runtime_disable(&pdev->dev); + + dss_uninit_ports(pdev); + + if (dss.video1_pll) + dss_video_pll_uninit(dss.video1_pll); + + if (dss.video2_pll) + dss_video_pll_uninit(dss.video2_pll); + + dss_put_clocks(); + return 0; }