From 0290c4ca2536a35e55c53cfb9058465b1f987b17 Mon Sep 17 00:00:00 2001 From: Frank Rowand Date: Tue, 17 Oct 2017 16:36:23 -0700 Subject: of: overlay: rename identifiers to more reflect what they do This patch is aimed primarily at drivers/of/overlay.c, but those changes also have a small impact in a few other files. overlay.c is difficult to read and maintain. Improve readability: - Rename functions, types and variables to better reflect what they do and to be consistent with names in other places, such as the device tree overlay FDT (flattened device tree), and make the algorithms more clear - Use the same names consistently throughout the file - Update comments for name changes - Fix incorrect comments This patch is intended to not introduce any functional change. Signed-off-by: Frank Rowand Signed-off-by: Rob Herring --- drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c index 623a9140493c..5f5b7ba35f1d 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c @@ -247,9 +247,10 @@ static void __init tilcdc_convert_slave_node(void) tilcdc_node_disable(slave); - ret = of_overlay_create(overlay); + ret = of_overlay_apply(overlay); if (ret) - pr_err("%s: Creating overlay failed: %d\n", __func__, ret); + pr_err("%s: Applying overlay changeset failed: %d\n", + __func__, ret); else pr_info("%s: ti,tilcdc,slave node successfully converted\n", __func__); -- cgit From 24789c5ce5a373dd55640f9cd79117fcc3ccc46d Mon Sep 17 00:00:00 2001 From: Frank Rowand Date: Tue, 17 Oct 2017 16:36:26 -0700 Subject: of: overlay: detect cases where device tree may become corrupt When an attempt to apply an overlay changeset fails, an effort is made to revert any partial application of the changeset. When an attempt to remove an overlay changeset fails, an effort is made to re-apply any partial reversion of the changeset. The existing code does not check for failure to recover a failed overlay changeset application or overlay changeset revert. Add the missing checks and flag the devicetree as corrupt if the state of the devicetree can not be determined. Improve and expand the returned errors to more fully reflect the result of the effort to undo the partial effects of a failed attempt to apply or remove an overlay changeset. If the device tree might be corrupt, do not allow further attempts to apply or remove an overlay changeset. When creating an overlay changeset from an overlay device tree, add some additional warnings if the state of the overlay device tree is not as expected. Signed-off-by: Frank Rowand Signed-off-by: Rob Herring --- drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c index 5f5b7ba35f1d..7a7be0515bfd 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c @@ -204,7 +204,7 @@ static void __init tilcdc_convert_slave_node(void) /* For all memory needed for the overlay tree. This memory can be freed after the overlay has been applied. */ struct kfree_table kft; - int ret; + int ovcs_id, ret; if (kfree_table_init(&kft)) return; @@ -247,7 +247,8 @@ static void __init tilcdc_convert_slave_node(void) tilcdc_node_disable(slave); - ret = of_overlay_apply(overlay); + ovcs_id = 0; + ret = of_overlay_apply(overlay, &ovcs_id); if (ret) pr_err("%s: Applying overlay changeset failed: %d\n", __func__, ret); -- cgit From f948d6d8b792bb90041edc12eac35faf83030994 Mon Sep 17 00:00:00 2001 From: Frank Rowand Date: Tue, 17 Oct 2017 16:36:29 -0700 Subject: of: overlay: avoid race condition between applying multiple overlays The process of applying an overlay consists of: - unflatten an overlay FDT (flattened device tree) into an EDT (expanded device tree) - fixup the phandle values in the overlay EDT to fit in a range above the phandle values in the live device tree - create the overlay changeset to reflect the contents of the overlay EDT - apply the overlay changeset, to modify the live device tree, potentially changing the maximum phandle value in the live device tree There is currently no protection against two overlay applies concurrently determining what range of phandle values are in use in the live device tree, and subsequently changing that range. Add a mutex to prevent multiple overlay applies from occurring simultaneously. Move of_resolve_phandles() into of_overlay_apply() so that it does not have to be duplicated by each caller of of_overlay_apply(). The test in of_resolve_phandles() that the overlay tree is detached is temporarily disabled so that old style overlay unittests do not fail. Signed-off-by: Frank Rowand Signed-off-by: Rob Herring --- drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c index 7a7be0515bfd..54025af534d4 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_slave_compat.c @@ -145,7 +145,6 @@ static struct device_node * __init tilcdc_get_overlay(struct kfree_table *kft) __dtb_tilcdc_slave_compat_begin; static void *overlay_data; struct device_node *overlay; - int ret; if (!size) { pr_warn("%s: No overlay data\n", __func__); @@ -164,11 +163,6 @@ static struct device_node * __init tilcdc_get_overlay(struct kfree_table *kft) } of_node_set_flag(overlay, OF_DETACHED); - ret = of_resolve_phandles(overlay); - if (ret) { - pr_err("%s: Failed to resolve phandles: %d\n", __func__, ret); - return NULL; - } return overlay; } -- cgit