From bce7698e2e6565bb765bd0522337f29f5f312624 Mon Sep 17 00:00:00 2001 From: Haojie Li Date: Tue, 25 Aug 2026 18:08:45 +0800 Subject: drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform device platform_device_register_data() can fail and return an ERR_PTR, but the return value is used without checking, leading to an invalid pointer being stored in ddp_comp[].dev and passed to component_match_add() and mtk_ddp_comp_init(), which could result in a kernel crash. Add an IS_ERR() check to jump to the error handling path on failure. Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195") Cc: stable@vger.kernel.org Signed-off-by: Haojie Li Reviewed-by: CK Hu Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/ Signed-off-by: Chun-Kuang Hu --- block/blk-pm.c | 191 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 191 insertions(+) create mode 100644 block/blk-pm.c (limited to 'block/blk-pm.c') diff --git a/block/blk-pm.c b/block/blk-pm.c new file mode 100644 index 000000000..8d3e052f9 --- /dev/null +++ b/block/blk-pm.c @@ -0,0 +1,191 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include "blk-mq.h" + +/** + * blk_pm_runtime_init - Block layer runtime PM initialization routine + * @q: the queue of the device + * @dev: the device the queue belongs to + * + * Description: + * Initialize runtime-PM-related fields for @q and start auto suspend for + * @dev. Drivers that want to take advantage of request-based runtime PM + * should call this function after @dev has been initialized, and its + * request queue @q has been allocated, and runtime PM for it can not happen + * yet(either due to disabled/forbidden or its usage_count > 0). In most + * cases, driver should call this function before any I/O has taken place. + * + * This function takes care of setting up using auto suspend for the device, + * the autosuspend delay is set to -1 to make runtime suspend impossible + * until an updated value is either set by user or by driver. Drivers do + * not need to touch other autosuspend settings. + * + * The block layer runtime PM is request based, so only works for drivers + * that use request as their IO unit instead of those directly use bio's. + */ +void blk_pm_runtime_init(struct request_queue *q, struct device *dev) +{ + q->dev = dev; + q->rpm_status = RPM_ACTIVE; + pm_runtime_set_autosuspend_delay(q->dev, -1); + pm_runtime_use_autosuspend(q->dev); +} +EXPORT_SYMBOL(blk_pm_runtime_init); + +/** + * blk_pre_runtime_suspend - Pre runtime suspend check + * @q: the queue of the device + * + * Description: + * This function will check if runtime suspend is allowed for the device + * by examining if there are any requests pending in the queue. If there + * are requests pending, the device can not be runtime suspended; otherwise, + * the queue's status will be updated to SUSPENDING and the driver can + * proceed to suspend the device. + * + * For the not allowed case, we mark last busy for the device so that + * runtime PM core will try to autosuspend it some time later. + * + * This function should be called near the start of the device's + * runtime_suspend callback. + * + * Return: + * 0 - OK to runtime suspend the device + * -EBUSY - Device should not be runtime suspended + */ +int blk_pre_runtime_suspend(struct request_queue *q) +{ + int ret = 0; + + if (!q->dev) + return ret; + + WARN_ON_ONCE(q->rpm_status != RPM_ACTIVE); + + spin_lock_irq(&q->queue_lock); + q->rpm_status = RPM_SUSPENDING; + spin_unlock_irq(&q->queue_lock); + + /* + * Increase the pm_only counter before checking whether any + * non-PM blk_queue_enter() calls are in progress to avoid that any + * new non-PM blk_queue_enter() calls succeed before the pm_only + * counter is decreased again. + */ + blk_set_pm_only(q); + ret = -EBUSY; + /* Switch q_usage_counter from per-cpu to atomic mode. */ + blk_freeze_queue_start(q); + /* + * Wait until atomic mode has been reached. Since that + * involves calling call_rcu(), it is guaranteed that later + * blk_queue_enter() calls see the pm-only state. See also + * http://lwn.net/Articles/573497/. + */ + percpu_ref_switch_to_atomic_sync(&q->q_usage_counter); + if (percpu_ref_is_zero(&q->q_usage_counter)) + ret = 0; + /* Switch q_usage_counter back to per-cpu mode. */ + blk_mq_unfreeze_queue_nomemrestore(q); + + if (ret < 0) { + spin_lock_irq(&q->queue_lock); + q->rpm_status = RPM_ACTIVE; + pm_runtime_mark_last_busy(q->dev); + spin_unlock_irq(&q->queue_lock); + + blk_clear_pm_only(q); + } + + return ret; +} +EXPORT_SYMBOL(blk_pre_runtime_suspend); + +/** + * blk_post_runtime_suspend - Post runtime suspend processing + * @q: the queue of the device + * @err: return value of the device's runtime_suspend function + * + * Description: + * Update the queue's runtime status according to the return value of the + * device's runtime suspend function and mark last busy for the device so + * that PM core will try to auto suspend the device at a later time. + * + * This function should be called near the end of the device's + * runtime_suspend callback. + */ +void blk_post_runtime_suspend(struct request_queue *q, int err) +{ + if (!q->dev) + return; + + spin_lock_irq(&q->queue_lock); + if (!err) { + q->rpm_status = RPM_SUSPENDED; + } else { + q->rpm_status = RPM_ACTIVE; + pm_runtime_mark_last_busy(q->dev); + } + spin_unlock_irq(&q->queue_lock); + + if (err) + blk_clear_pm_only(q); +} +EXPORT_SYMBOL(blk_post_runtime_suspend); + +/** + * blk_pre_runtime_resume - Pre runtime resume processing + * @q: the queue of the device + * + * Description: + * Update the queue's runtime status to RESUMING in preparation for the + * runtime resume of the device. + * + * This function should be called near the start of the device's + * runtime_resume callback. + */ +void blk_pre_runtime_resume(struct request_queue *q) +{ + if (!q->dev) + return; + + spin_lock_irq(&q->queue_lock); + q->rpm_status = RPM_RESUMING; + spin_unlock_irq(&q->queue_lock); +} +EXPORT_SYMBOL(blk_pre_runtime_resume); + +/** + * blk_post_runtime_resume - Post runtime resume processing + * @q: the queue of the device + * + * Description: + * Restart the queue of a runtime suspended device. It does this regardless + * of whether the device's runtime-resume succeeded; even if it failed the + * driver or error handler will need to communicate with the device. + * + * This function should be called near the end of the device's + * runtime_resume callback to correct queue runtime PM status and re-enable + * peeking requests from the queue. + */ +void blk_post_runtime_resume(struct request_queue *q) +{ + int old_status; + + if (!q->dev) + return; + + spin_lock_irq(&q->queue_lock); + old_status = q->rpm_status; + q->rpm_status = RPM_ACTIVE; + pm_runtime_mark_last_busy(q->dev); + pm_request_autosuspend(q->dev); + spin_unlock_irq(&q->queue_lock); + + if (old_status != RPM_ACTIVE) + blk_clear_pm_only(q); +} +EXPORT_SYMBOL(blk_post_runtime_resume); -- cgit v1.3.1