On 02/05/2022 16:25, Thomas Zimmermann wrote:
Add a mutex lock to protect concurrent access to I/O registers against each other. This happens between invokataion of commit-
Typo in commit message, invokataion => invocation
tail functions and get-mode operations. Both with use the CRTC index registers MGA1064_GEN_IO_DATA and MGA1064_GEN_IO_CTL. Concurrent access can lead to failed mode-setting operations.
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de
There is a trivial conflict with https://lists.freedesktop.org/archives/dri-devel/2022-April/352966.html But I will need to send a v2 for it anyway.
It looks good to me, Reviewed-by: Jocelyn Falempe jfalempe@redhat.com
drivers/gpu/drm/mgag200/mgag200_drv.c | 6 ++++++ drivers/gpu/drm/mgag200/mgag200_drv.h | 1 + drivers/gpu/drm/mgag200/mgag200_mode.c | 14 ++++++++++++++ 3 files changed, 21 insertions(+)
diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.c b/drivers/gpu/drm/mgag200/mgag200_drv.c index 217844d71ab5c..08839460606fe 100644 --- a/drivers/gpu/drm/mgag200/mgag200_drv.c +++ b/drivers/gpu/drm/mgag200/mgag200_drv.c @@ -14,6 +14,7 @@ #include <drm/drm_drv.h> #include <drm/drm_file.h> #include <drm/drm_ioctl.h> +#include <drm/drm_managed.h> #include <drm/drm_module.h> #include <drm/drm_pciids.h>
@@ -65,6 +66,11 @@ static int mgag200_regs_init(struct mga_device *mdev) struct pci_dev *pdev = to_pci_dev(dev->dev); u32 option, option2; u8 crtcext3;
int ret;
ret = drmm_mutex_init(dev, &mdev->rmmio_lock);
if (ret)
return ret;switch (mdev->type) { case G200_PCI:
diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h index 4368112023f7c..18829eb8398a0 100644 --- a/drivers/gpu/drm/mgag200/mgag200_drv.h +++ b/drivers/gpu/drm/mgag200/mgag200_drv.h @@ -213,6 +213,7 @@ struct mga_device { struct drm_device base; unsigned long flags;
- struct mutex rmmio_lock; resource_size_t rmmio_base; resource_size_t rmmio_size; void __iomem *rmmio;
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c index 6e18d3bbd7207..abde7655477db 100644 --- a/drivers/gpu/drm/mgag200/mgag200_mode.c +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c @@ -881,6 +881,14 @@ mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe, .y2 = fb->height, };
- /*
* Concurrent operations could possibly trigger a call to* drm_connector_helper_funcs.get_modes by trying to read the* display modes. Protect access to I/O registers by acquiring* the I/O-register lock.*/- mutex_lock(&mdev->rmmio_lock);
- if (mdev->type == G200_WB || mdev->type == G200_EW3) mgag200_g200wb_hold_bmc(mdev);
@@ -904,6 +912,8 @@ mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe, mgag200_enable_display(mdev);
mgag200_handle_damage(mdev, fb, &fullscreen, &shadow_plane_state->data[0]);
mutex_unlock(&mdev->rmmio_lock); }
static void
@@ -963,8 +973,12 @@ mgag200_simple_display_pipe_update(struct drm_simple_display_pipe *pipe, if (!fb) return;
mutex_lock(&mdev->rmmio_lock);
if (drm_atomic_helper_damage_merged(old_state, state, &damage)) mgag200_handle_damage(mdev, fb, &damage, &shadow_plane_state->data[0]);
mutex_unlock(&mdev->rmmio_lock); }
static struct drm_crtc_state *