From 8f12a3118f554d2a38cc2c0ea17443d8b041b17f Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Sun, 23 Aug 2015 23:23:02 +0200 Subject: [PATCH] vga_switcheroo: Add missing locking The following functions iterate over the client list, invoke client callbacks or invoke handler callbacks without locking anything at all: - Introduced by c8e9cf7bb240 ("vga_switcheroo: Add a helper function to get the client state"): vga_switcheroo_get_client_state() - Introduced by 0d69704ae348 ("gpu/vga_switcheroo: add driver control power feature. (v3)"): vga_switcheroo_set_dynamic_switch() vga_switcheroo_runtime_suspend() vga_switcheroo_runtime_resume() vga_switcheroo_runtime_resume_hdmi_audio() Refactor vga_switcheroo_runtime_resume_hdmi_audio() a bit to be able to release vgasr_mutex immediately after iterating over the client list. Signed-off-by: Lukas Wunner Signed-off-by: Daniel Vetter --- drivers/gpu/vga/vga_switcheroo.c | 50 ++++++++++++++++++++------------ 1 file changed, 32 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c index 86c03b53e7bf..1acbe20143d4 100644 --- a/drivers/gpu/vga/vga_switcheroo.c +++ b/drivers/gpu/vga/vga_switcheroo.c @@ -347,13 +347,18 @@ find_active_client(struct list_head *head) int vga_switcheroo_get_client_state(struct pci_dev *pdev) { struct vga_switcheroo_client *client; + enum vga_switcheroo_state ret; + mutex_lock(&vgasr_mutex); client = find_client_from_pci(&vgasr_priv.clients, pdev); if (!client) - return VGA_SWITCHEROO_NOT_FOUND; - if (!vgasr_priv.active) - return VGA_SWITCHEROO_INIT; - return client->pwr_state; + ret = VGA_SWITCHEROO_NOT_FOUND; + else if (!vgasr_priv.active) + ret = VGA_SWITCHEROO_INIT; + else + ret = client->pwr_state; + mutex_unlock(&vgasr_mutex); + return ret; } EXPORT_SYMBOL(vga_switcheroo_get_client_state); @@ -845,15 +850,16 @@ void vga_switcheroo_set_dynamic_switch(struct pci_dev *pdev, { struct vga_switcheroo_client *client; + mutex_lock(&vgasr_mutex); client = find_client_from_pci(&vgasr_priv.clients, pdev); - if (!client) - return; - - if (!client->driver_power_control) + if (!client || !client->driver_power_control) { + mutex_unlock(&vgasr_mutex); return; + } client->pwr_state = dynamic; set_audio_state(client->id, dynamic); + mutex_unlock(&vgasr_mutex); } EXPORT_SYMBOL(vga_switcheroo_set_dynamic_switch); @@ -866,9 +872,11 @@ static int vga_switcheroo_runtime_suspend(struct device *dev) ret = dev->bus->pm->runtime_suspend(dev); if (ret) return ret; + mutex_lock(&vgasr_mutex); if (vgasr_priv.handler->switchto) vgasr_priv.handler->switchto(VGA_SWITCHEROO_IGD); vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_OFF); + mutex_unlock(&vgasr_mutex); return 0; } @@ -877,7 +885,9 @@ static int vga_switcheroo_runtime_resume(struct device *dev) struct pci_dev *pdev = to_pci_dev(dev); int ret; + mutex_lock(&vgasr_mutex); vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_ON); + mutex_unlock(&vgasr_mutex); ret = dev->bus->pm->runtime_resume(dev); if (ret) return ret; @@ -923,29 +933,33 @@ EXPORT_SYMBOL(vga_switcheroo_fini_domain_pm_ops); static int vga_switcheroo_runtime_resume_hdmi_audio(struct device *dev) { struct pci_dev *pdev = to_pci_dev(dev); + struct vga_switcheroo_client *client; + struct device *video_dev = NULL; int ret; - struct vga_switcheroo_client *client, *found = NULL; /* we need to check if we have to switch back on the video device so the audio device can come back */ + mutex_lock(&vgasr_mutex); list_for_each_entry(client, &vgasr_priv.clients, list) { if (PCI_SLOT(client->pdev->devfn) == PCI_SLOT(pdev->devfn) && client_is_vga(client)) { - found = client; - ret = pm_runtime_get_sync(&client->pdev->dev); - if (ret) { - if (ret != 1) - return ret; - } + video_dev = &client->pdev->dev; break; } } + mutex_unlock(&vgasr_mutex); + + if (video_dev) { + ret = pm_runtime_get_sync(video_dev); + if (ret && ret != 1) + return ret; + } ret = dev->bus->pm->runtime_resume(dev); /* put the reference for the gpu */ - if (found) { - pm_runtime_mark_last_busy(&found->pdev->dev); - pm_runtime_put_autosuspend(&found->pdev->dev); + if (video_dev) { + pm_runtime_mark_last_busy(video_dev); + pm_runtime_put_autosuspend(video_dev); } return ret; } -- 2.34.1