From c6432ea9cc043994d5b7dcb3ad86a087777cb40c Mon Sep 17 00:00:00 2001 From: Dimitris Papastamos Date: Mon, 11 Mar 2013 17:27:02 +0000 Subject: regmap: Initialize `map->debugfs' before regcache In the rbtree code we are exposing statistics relating to the number of nodes/registers of the rbtree cache for each of the devices. Ensure that `map->debugfs' has been initialized before we attempt to initialize the debugfs entry for the rbtree cache. Signed-off-by: Dimitris Papastamos Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/base/regmap/regmap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 3d2367501fd0..50ef277ea4b6 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -710,12 +710,12 @@ skip_format_initialization: } } + regmap_debugfs_init(map, config->name); + ret = regcache_init(map, config); if (ret != 0) goto err_range; - regmap_debugfs_init(map, config->name); - /* Add a devres resource for dev_get_regmap() */ m = devres_alloc(dev_get_regmap_release, sizeof(*m), GFP_KERNEL); if (!m) { -- cgit v1.2.3 From 8abac3ba51b5525354e9b2ec0eed1c9e95c905d9 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Wed, 13 Mar 2013 16:38:33 +0100 Subject: regmap: cache Fix regcache-rbtree sync The last register block, which falls into the specified range, is not handled correctly. The formula which calculates the number of register which should be synced is inverse (and off by one). E.g. if all registers in that block should be synced only one is synced, and if only one should be synced all (but one) are synced. To calculate the number of registers that need to be synced we need to subtract the number of the first register in the block from the max register number and add one. This patch updates the code accordingly. The issue was introduced in commit ac8d91c ("regmap: Supply ranges to the sync operations"). Signed-off-by: Lars-Peter Clausen Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/base/regmap/regcache-rbtree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c index e6732cf7c06e..79f4fca9877a 100644 --- a/drivers/base/regmap/regcache-rbtree.c +++ b/drivers/base/regmap/regcache-rbtree.c @@ -398,7 +398,7 @@ static int regcache_rbtree_sync(struct regmap *map, unsigned int min, base = 0; if (max < rbnode->base_reg + rbnode->blklen) - end = rbnode->base_reg + rbnode->blklen - max; + end = max - rbnode->base_reg + 1; else end = rbnode->blklen; -- cgit v1.2.3 From bc8ce4afd7ee7e1421c935d24b1f879f82afdd4e Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Wed, 20 Mar 2013 17:02:02 -0600 Subject: regmap: don't corrupt work buffer in _regmap_raw_write() _regmap_raw_write() contains code to call regcache_write() to write values to the cache. That code calls memcpy() to copy the value data to the start of the work_buf. However, at least when _regmap_raw_write() is called from _regmap_bus_raw_write(), the value data is in the work_buf, and this memcpy() operation may over-write part of that value data, depending on the value of reg_bytes + pad_bytes. At least when using reg_bytes==1 and pad_bytes==0, corruption of the value data does occur. To solve this, remove the memcpy() operation, and modify the subsequent .parse_val() call to parse the original value buffer directly. At least in the case of 8-bit register address and 16-bit values, and writes of single registers at a time, this memcpy-then-parse combination used to cancel each-other out; for a work-buffer containing xx 89 03, the memcpy changed it to 89 03 03, and the parse_val changed it back to 89 89 03, thus leaving the value uncorrupted. This appears completely accidental though. Since commit 8a819ff "regmap: core: Split out in place value parsing", .parse_val only returns the parsed value, and does not modify the buffer, and hence does not (accidentally) undo the corruption caused by memcpy(). This caused bogus values to get written to HW, thus preventing e.g. audio playback on systems with a WM8903 CODEC. This patch fixes that. Signed-off-by: Stephen Warren Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 3d2367501fd0..89a920510e1d 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -943,8 +943,7 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg, unsigned int ival; int val_bytes = map->format.val_bytes; for (i = 0; i < val_len / val_bytes; i++) { - memcpy(map->work_buf, val + (i * val_bytes), val_bytes); - ival = map->format.parse_val(map->work_buf); + ival = map->format.parse_val(val + (i * val_bytes)); ret = regcache_write(map, reg + (i * map->reg_stride), ival); if (ret) { -- cgit v1.2.3 From f951b6587b94df2abb8c7a2425f7dcdb4fe647dc Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 27 Mar 2013 13:08:44 +0000 Subject: regmap: async: Add missing return Let's only write once... Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/base') diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 3d2367501fd0..dd82acfbcf4e 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1036,6 +1036,8 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg, kfree(async->work_buf); kfree(async); } + + return ret; } trace_regmap_hw_write_start(map->dev, reg, -- cgit v1.2.3 From 0f703069296664eb7c649c837cc8bb936c3ef07f Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 2 Apr 2013 01:25:24 +0200 Subject: PM / QoS: Avoid possible deadlock related to sysfs access Commit b81ea1b (PM / QoS: Fix concurrency issues and memory leaks in device PM QoS) put calls to pm_qos_sysfs_add_latency(), pm_qos_sysfs_add_flags(), pm_qos_sysfs_remove_latency(), and pm_qos_sysfs_remove_flags() under dev_pm_qos_mtx, which was a mistake, because it may lead to deadlocks in some situations. For example, if pm_qos_remote_wakeup_store() is run in parallel with dev_pm_qos_constraints_destroy(), they may deadlock in the following way: ====================================================== [ INFO: possible circular locking dependency detected ] 3.9.0-rc4-next-20130328-sasha-00014-g91a3267 #319 Tainted: G W ------------------------------------------------------- trinity-child6/12371 is trying to acquire lock: (s_active#54){++++.+}, at: [] sysfs_addrm_finish+0x31/0x60 but task is already holding lock: (dev_pm_qos_mtx){+.+.+.}, at: [] dev_pm_qos_constraints_destroy+0x23/0x250 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (dev_pm_qos_mtx){+.+.+.}: [] lock_acquire+0x1aa/0x240 [] __mutex_lock_common+0x59/0x5e0 [] mutex_lock_nested+0x3f/0x50 [] dev_pm_qos_update_flags+0x3f/0xc0 [] pm_qos_remote_wakeup_store+0x3f/0x70 [] dev_attr_store+0x13/0x20 [] sysfs_write_file+0xfa/0x150 [] __kernel_write+0x81/0x150 [] write_pipe_buf+0x4d/0x80 [] splice_from_pipe_feed+0x7c/0x120 [] __splice_from_pipe+0x45/0x80 [] splice_from_pipe+0x4c/0x70 [] default_file_splice_write+0x18/0x30 [] do_splice_from+0x83/0xb0 [] direct_splice_actor+0x1e/0x20 [] splice_direct_to_actor+0xe7/0x200 [] do_splice_direct+0x4c/0x70 [] do_sendfile+0x169/0x300 [] SyS_sendfile64+0x64/0xb0 [] tracesys+0xe1/0xe6 -> #0 (s_active#54){++++.+}: [] __lock_acquire+0x15bf/0x1e50 [] lock_acquire+0x1aa/0x240 [] sysfs_deactivate+0x122/0x1a0 [] sysfs_addrm_finish+0x31/0x60 [] sysfs_hash_and_remove+0x7f/0xb0 [] sysfs_unmerge_group+0x51/0x70 [] pm_qos_sysfs_remove_flags+0x14/0x20 [] __dev_pm_qos_hide_flags+0x30/0x70 [] dev_pm_qos_constraints_destroy+0x35/0x250 [] dpm_sysfs_remove+0x11/0x50 [] device_del+0x3f/0x1b0 [] device_unregister+0x48/0x60 [] usb_hub_remove_port_device+0x1c/0x20 [] hub_disconnect+0xdd/0x160 [] usb_unbind_interface+0x67/0x170 [] __device_release_driver+0x87/0xe0 [] device_release_driver+0x29/0x40 [] bus_remove_device+0x148/0x160 [] device_del+0x14f/0x1b0 [] usb_disable_device+0xf9/0x280 [] usb_set_configuration+0x268/0x840 [] usb_remove_store+0x4c/0x80 [] dev_attr_store+0x13/0x20 [] sysfs_write_file+0xfa/0x150 [] do_loop_readv_writev+0x4d/0x90 [] do_readv_writev+0xf9/0x1e0 [] vfs_writev+0x3a/0x60 [] SyS_writev+0x50/0xd0 [] tracesys+0xe1/0xe6 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(dev_pm_qos_mtx); lock(s_active#54); lock(dev_pm_qos_mtx); lock(s_active#54); *** DEADLOCK *** To avoid that, remove the calls to functions mentioned above from under dev_pm_qos_mtx and introduce a separate lock to prevent races between functions that add or remove device PM QoS sysfs attributes from happening. Reported-by: Sasha Levin Signed-off-by: Rafael J. Wysocki --- drivers/base/power/qos.c | 60 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 47 insertions(+), 13 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index 5f74587ef258..71671c42ef45 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -46,6 +46,7 @@ #include "power.h" static DEFINE_MUTEX(dev_pm_qos_mtx); +static DEFINE_MUTEX(dev_pm_qos_sysfs_mtx); static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers); @@ -216,12 +217,17 @@ void dev_pm_qos_constraints_destroy(struct device *dev) struct pm_qos_constraints *c; struct pm_qos_flags *f; - mutex_lock(&dev_pm_qos_mtx); + mutex_lock(&dev_pm_qos_sysfs_mtx); /* * If the device's PM QoS resume latency limit or PM QoS flags have been * exposed to user space, they have to be hidden at this point. */ + pm_qos_sysfs_remove_latency(dev); + pm_qos_sysfs_remove_flags(dev); + + mutex_lock(&dev_pm_qos_mtx); + __dev_pm_qos_hide_latency_limit(dev); __dev_pm_qos_hide_flags(dev); @@ -254,6 +260,8 @@ void dev_pm_qos_constraints_destroy(struct device *dev) out: mutex_unlock(&dev_pm_qos_mtx); + + mutex_unlock(&dev_pm_qos_sysfs_mtx); } /** @@ -558,6 +566,14 @@ static void __dev_pm_qos_drop_user_request(struct device *dev, kfree(req); } +static void dev_pm_qos_drop_user_request(struct device *dev, + enum dev_pm_qos_req_type type) +{ + mutex_lock(&dev_pm_qos_mtx); + __dev_pm_qos_drop_user_request(dev, type); + mutex_unlock(&dev_pm_qos_mtx); +} + /** * dev_pm_qos_expose_latency_limit - Expose PM QoS latency limit to user space. * @dev: Device whose PM QoS latency limit is to be exposed to user space. @@ -581,6 +597,8 @@ int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value) return ret; } + mutex_lock(&dev_pm_qos_sysfs_mtx); + mutex_lock(&dev_pm_qos_mtx); if (IS_ERR_OR_NULL(dev->power.qos)) @@ -591,26 +609,27 @@ int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value) if (ret < 0) { __dev_pm_qos_remove_request(req); kfree(req); + mutex_unlock(&dev_pm_qos_mtx); goto out; } - dev->power.qos->latency_req = req; + + mutex_unlock(&dev_pm_qos_mtx); + ret = pm_qos_sysfs_add_latency(dev); if (ret) - __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY); + dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY); out: - mutex_unlock(&dev_pm_qos_mtx); + mutex_unlock(&dev_pm_qos_sysfs_mtx); return ret; } EXPORT_SYMBOL_GPL(dev_pm_qos_expose_latency_limit); static void __dev_pm_qos_hide_latency_limit(struct device *dev) { - if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->latency_req) { - pm_qos_sysfs_remove_latency(dev); + if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->latency_req) __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_LATENCY); - } } /** @@ -619,9 +638,15 @@ static void __dev_pm_qos_hide_latency_limit(struct device *dev) */ void dev_pm_qos_hide_latency_limit(struct device *dev) { + mutex_lock(&dev_pm_qos_sysfs_mtx); + + pm_qos_sysfs_remove_latency(dev); + mutex_lock(&dev_pm_qos_mtx); __dev_pm_qos_hide_latency_limit(dev); mutex_unlock(&dev_pm_qos_mtx); + + mutex_unlock(&dev_pm_qos_sysfs_mtx); } EXPORT_SYMBOL_GPL(dev_pm_qos_hide_latency_limit); @@ -649,6 +674,8 @@ int dev_pm_qos_expose_flags(struct device *dev, s32 val) } pm_runtime_get_sync(dev); + mutex_lock(&dev_pm_qos_sysfs_mtx); + mutex_lock(&dev_pm_qos_mtx); if (IS_ERR_OR_NULL(dev->power.qos)) @@ -659,16 +686,19 @@ int dev_pm_qos_expose_flags(struct device *dev, s32 val) if (ret < 0) { __dev_pm_qos_remove_request(req); kfree(req); + mutex_unlock(&dev_pm_qos_mtx); goto out; } - dev->power.qos->flags_req = req; + + mutex_unlock(&dev_pm_qos_mtx); + ret = pm_qos_sysfs_add_flags(dev); if (ret) - __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); + dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); out: - mutex_unlock(&dev_pm_qos_mtx); + mutex_unlock(&dev_pm_qos_sysfs_mtx); pm_runtime_put(dev); return ret; } @@ -676,10 +706,8 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_expose_flags); static void __dev_pm_qos_hide_flags(struct device *dev) { - if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req) { - pm_qos_sysfs_remove_flags(dev); + if (!IS_ERR_OR_NULL(dev->power.qos) && dev->power.qos->flags_req) __dev_pm_qos_drop_user_request(dev, DEV_PM_QOS_FLAGS); - } } /** @@ -689,9 +717,15 @@ static void __dev_pm_qos_hide_flags(struct device *dev) void dev_pm_qos_hide_flags(struct device *dev) { pm_runtime_get_sync(dev); + mutex_lock(&dev_pm_qos_sysfs_mtx); + + pm_qos_sysfs_remove_flags(dev); + mutex_lock(&dev_pm_qos_mtx); __dev_pm_qos_hide_flags(dev); mutex_unlock(&dev_pm_qos_mtx); + + mutex_unlock(&dev_pm_qos_sysfs_mtx); pm_runtime_put(dev); } EXPORT_SYMBOL_GPL(dev_pm_qos_hide_flags); -- cgit v1.2.3 From 51a246aa5c0a14b3d34a5c6d3c9e271c784b127f Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Tue, 9 Apr 2013 18:03:25 +0100 Subject: regmap: Back out work buffer fix This reverts commit bc8ce4 (regmap: don't corrupt work buffer in _regmap_raw_write()) since it turns out that it can cause issues when taken in isolation from the other changes in -next that lead to its discovery. On the basis that nobody noticed the problems for quite some time without that subsequent work let's drop it from v3.9. Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/base') diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index d34adef1e63e..58cfb3232428 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -943,7 +943,8 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg, unsigned int ival; int val_bytes = map->format.val_bytes; for (i = 0; i < val_len / val_bytes; i++) { - ival = map->format.parse_val(val + (i * val_bytes)); + memcpy(map->work_buf, val + (i * val_bytes), val_bytes); + ival = map->format.parse_val(map->work_buf); ret = regcache_write(map, reg + (i * map->reg_stride), ival); if (ret) { -- cgit v1.2.3