5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Georgi Djakov <georgi.djakov@xxxxxxxxxx> [ Upstream commit 7d374b20908338c9fbb03ea8022a11f3b3e0e55f ] There is a repeated pattern in multiple drivers where they want to switch the bandwidth between zero and some other value. This is happening often in the suspend/resume callbacks. Let's add helper functions to enable and disable the path, so that callers don't have to take care of remembering the bandwidth values and handle this in the framework instead. With this patch the users can call icc_disable() and icc_enable() to lower their bandwidth request to zero and then restore it back to it's previous value. Suggested-by: Evan Green <evgreen@xxxxxxxxxxxx> Suggested-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Signed-off-by: Georgi Djakov <georgi.djakov@xxxxxxxxxx> Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200507120846.8354-1-georgi.djakov@xxxxxxxxxx Signed-off-by: Georgi Djakov <georgi.djakov@xxxxxxxxxx> Stable-dep-of: d2d69354226d ("USB: dwc3: qcom: fix NULL-deref on suspend") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/interconnect/core.c | 39 ++++++++++++++++++++++++++++++++- drivers/interconnect/internal.h | 2 ++ include/linux/interconnect.h | 12 ++++++++++ 3 files changed, 52 insertions(+), 1 deletion(-) diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c index 25dd8a19139a7..112298100d370 100644 --- a/drivers/interconnect/core.c +++ b/drivers/interconnect/core.c @@ -91,6 +91,7 @@ static struct icc_path *path_init(struct device *dev, struct icc_node *dst, hlist_add_head(&path->reqs[i].req_node, &node->req_list); path->reqs[i].node = node; path->reqs[i].dev = dev; + path->reqs[i].enabled = true; /* reference to previous node was saved during path traversal */ node = node->reverse; } @@ -182,9 +183,12 @@ static int aggregate_requests(struct icc_node *node) if (p->pre_aggregate) p->pre_aggregate(node); - hlist_for_each_entry(r, &node->req_list, req_node) + hlist_for_each_entry(r, &node->req_list, req_node) { + if (!r->enabled) + continue; p->aggregate(node, r->tag, r->avg_bw, r->peak_bw, &node->avg_bw, &node->peak_bw); + } return 0; } @@ -449,6 +453,39 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw) } EXPORT_SYMBOL_GPL(icc_set_bw); +static int __icc_enable(struct icc_path *path, bool enable) +{ + int i; + + if (!path) + return 0; + + if (WARN_ON(IS_ERR(path) || !path->num_nodes)) + return -EINVAL; + + mutex_lock(&icc_lock); + + for (i = 0; i < path->num_nodes; i++) + path->reqs[i].enabled = enable; + + mutex_unlock(&icc_lock); + + return icc_set_bw(path, path->reqs[0].avg_bw, + path->reqs[0].peak_bw); +} + +int icc_enable(struct icc_path *path) +{ + return __icc_enable(path, true); +} +EXPORT_SYMBOL_GPL(icc_enable); + +int icc_disable(struct icc_path *path) +{ + return __icc_enable(path, false); +} +EXPORT_SYMBOL_GPL(icc_disable); + /** * icc_get() - return a handle for path between two endpoints * @dev: the device requesting the path diff --git a/drivers/interconnect/internal.h b/drivers/interconnect/internal.h index 5853e8faf223a..5c923c444f444 100644 --- a/drivers/interconnect/internal.h +++ b/drivers/interconnect/internal.h @@ -14,6 +14,7 @@ * @req_node: entry in list of requests for the particular @node * @node: the interconnect node to which this constraint applies * @dev: reference to the device that sets the constraints + * @enabled: indicates whether the path with this request is enabled * @tag: path tag (optional) * @avg_bw: an integer describing the average bandwidth in kBps * @peak_bw: an integer describing the peak bandwidth in kBps @@ -22,6 +23,7 @@ struct icc_req { struct hlist_node req_node; struct icc_node *node; struct device *dev; + bool enabled; u32 tag; u32 avg_bw; u32 peak_bw; diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h index d70a914cba118..1e0dd0541b1ed 100644 --- a/include/linux/interconnect.h +++ b/include/linux/interconnect.h @@ -29,6 +29,8 @@ struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id); struct icc_path *of_icc_get(struct device *dev, const char *name); void icc_put(struct icc_path *path); +int icc_enable(struct icc_path *path); +int icc_disable(struct icc_path *path); int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw); void icc_set_tag(struct icc_path *path, u32 tag); @@ -50,6 +52,16 @@ static inline void icc_put(struct icc_path *path) { } +static inline int icc_enable(struct icc_path *path) +{ + return 0; +} + +static inline int icc_disable(struct icc_path *path) +{ + return 0; +} + static inline int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw) { return 0; -- 2.40.1
