From 9495b7e92f716ab2bd6814fab5e97ab4a39adfdd Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 22 Apr 2020 12:09:54 +0200 Subject: [PATCH 1/9] driver core: platform: Initialize dma_parms for platform devices It's currently the platform driver's responsibility to initialize the pointer, dma_parms, for its corresponding struct device. The benefit with this approach allows us to avoid the initialization and to not waste memory for the struct device_dma_parameters, as this can be decided on a case by case basis. However, it has turned out that this approach is not very practical. Not only does it lead to open coding, but also to real errors. In principle callers of dma_set_max_seg_size() doesn't check the error code, but just assumes it succeeds. For these reasons, let's do the initialization from the common platform bus at the device registration point. This also follows the way the PCI devices are being managed, see pci_device_add(). Suggested-by: Christoph Hellwig Cc: Tested-by: Haibo Chen Reviewed-by: Arnd Bergmann Signed-off-by: Ulf Hansson Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20200422100954.31211-1-ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 2 ++ include/linux/platform_device.h | 1 + 2 files changed, 3 insertions(+) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 5255550b7c34f..b27d0f6c18c9c 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -380,6 +380,8 @@ struct platform_object { */ static void setup_pdev_dma_masks(struct platform_device *pdev) { + pdev->dev.dma_parms = &pdev->dma_parms; + if (!pdev->dev.coherent_dma_mask) pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); if (!pdev->dev.dma_mask) { diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index bdc35753ef7c1..77a2aada106dc 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -25,6 +25,7 @@ struct platform_device { bool id_auto; struct device dev; u64 platform_dma_mask; + struct device_dma_parameters dma_parms; u32 num_resources; struct resource *resource; From f458488425f1cc9a396aa1d09bb00c48783936da Mon Sep 17 00:00:00 2001 From: Ulf Hansson Date: Wed, 22 Apr 2020 12:10:13 +0200 Subject: [PATCH 2/9] amba: Initialize dma_parms for amba devices It's currently the amba driver's responsibility to initialize the pointer, dma_parms, for its corresponding struct device. The benefit with this approach allows us to avoid the initialization and to not waste memory for the struct device_dma_parameters, as this can be decided on a case by case basis. However, it has turned out that this approach is not very practical. Not only does it lead to open coding, but also to real errors. In principle callers of dma_set_max_seg_size() doesn't check the error code, but just assumes it succeeds. For these reasons, let's do the initialization from the common amba bus at the device registration point. This also follows the way the PCI devices are being managed, see pci_device_add(). Suggested-by: Christoph Hellwig Cc: Russell King Cc: Tested-by: Haibo Chen Reviewed-by: Arnd Bergmann Signed-off-by: Ulf Hansson Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20200422101013.31267-1-ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/amba/bus.c | 1 + include/linux/amba/bus.h | 1 + 2 files changed, 2 insertions(+) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index fe1523664816a..8558b629880b1 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -645,6 +645,7 @@ static void amba_device_initialize(struct amba_device *dev, const char *name) dev->dev.release = amba_device_release; dev->dev.bus = &amba_bustype; dev->dev.dma_mask = &dev->dev.coherent_dma_mask; + dev->dev.dma_parms = &dev->dma_parms; dev->res.name = dev_name(&dev->dev); } diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h index 26f0ecf401eaa..0bbfd647f5c6d 100644 --- a/include/linux/amba/bus.h +++ b/include/linux/amba/bus.h @@ -65,6 +65,7 @@ struct amba_device { struct device dev; struct resource res; struct clk *pclk; + struct device_dma_parameters dma_parms; unsigned int periphid; unsigned int cid; struct amba_cs_uci_id uci; From 3740d93e37902b31159a82da2d5c8812ed825404 Mon Sep 17 00:00:00 2001 From: Luis Chamberlain Date: Thu, 16 Apr 2020 16:28:59 +0000 Subject: [PATCH 3/9] coredump: fix crash when umh is disabled Commit 64e90a8acb859 ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()") added the optiont to disable all call_usermodehelper() calls by setting STATIC_USERMODEHELPER_PATH to an empty string. When this is done, and crashdump is triggered, it will crash on null pointer dereference, since we make assumptions over what call_usermodehelper_exec() did. This has been reported by Sergey when one triggers a a coredump with the following configuration: ``` CONFIG_STATIC_USERMODEHELPER=y CONFIG_STATIC_USERMODEHELPER_PATH="" kernel.core_pattern = |/usr/lib/systemd/systemd-coredump %P %u %g %s %t %c %h %e ``` The way disabling the umh was designed was that call_usermodehelper_exec() would just return early, without an error. But coredump assumes certain variables are set up for us when this happens, and calls ile_start_write(cprm.file) with a NULL file. [ 2.819676] BUG: kernel NULL pointer dereference, address: 0000000000000020 [ 2.819859] #PF: supervisor read access in kernel mode [ 2.820035] #PF: error_code(0x0000) - not-present page [ 2.820188] PGD 0 P4D 0 [ 2.820305] Oops: 0000 [#1] SMP PTI [ 2.820436] CPU: 2 PID: 89 Comm: a Not tainted 5.7.0-rc1+ #7 [ 2.820680] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014 [ 2.821150] RIP: 0010:do_coredump+0xd80/0x1060 [ 2.821385] Code: e8 95 11 ed ff 48 c7 c6 cc a7 b4 81 48 8d bd 28 ff ff ff 89 c2 e8 70 f1 ff ff 41 89 c2 85 c0 0f 84 72 f7 ff ff e9 b4 fe ff ff <48> 8b 57 20 0f b7 02 66 25 00 f0 66 3d 00 8 0 0f 84 9c 01 00 00 44 [ 2.822014] RSP: 0000:ffffc9000029bcb8 EFLAGS: 00010246 [ 2.822339] RAX: 0000000000000000 RBX: ffff88803f860000 RCX: 000000000000000a [ 2.822746] RDX: 0000000000000009 RSI: 0000000000000282 RDI: 0000000000000000 [ 2.823141] RBP: ffffc9000029bde8 R08: 0000000000000000 R09: ffffc9000029bc00 [ 2.823508] R10: 0000000000000001 R11: ffff88803dec90be R12: ffffffff81c39da0 [ 2.823902] R13: ffff88803de84400 R14: 0000000000000000 R15: 0000000000000000 [ 2.824285] FS: 00007fee08183540(0000) GS:ffff88803e480000(0000) knlGS:0000000000000000 [ 2.824767] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.825111] CR2: 0000000000000020 CR3: 000000003f856005 CR4: 0000000000060ea0 [ 2.825479] Call Trace: [ 2.825790] get_signal+0x11e/0x720 [ 2.826087] do_signal+0x1d/0x670 [ 2.826361] ? force_sig_info_to_task+0xc1/0xf0 [ 2.826691] ? force_sig_fault+0x3c/0x40 [ 2.826996] ? do_trap+0xc9/0x100 [ 2.827179] exit_to_usermode_loop+0x49/0x90 [ 2.827359] prepare_exit_to_usermode+0x77/0xb0 [ 2.827559] ? invalid_op+0xa/0x30 [ 2.827747] ret_from_intr+0x20/0x20 [ 2.827921] RIP: 0033:0x55e2c76d2129 [ 2.828107] Code: 2d ff ff ff e8 68 ff ff ff 5d c6 05 18 2f 00 00 01 c3 0f 1f 80 00 00 00 00 c3 0f 1f 80 00 00 00 00 e9 7b ff ff ff 55 48 89 e5 <0f> 0b b8 00 00 00 00 5d c3 66 2e 0f 1f 84 0 0 00 00 00 00 0f 1f 40 [ 2.828603] RSP: 002b:00007fffeba5e080 EFLAGS: 00010246 [ 2.828801] RAX: 000055e2c76d2125 RBX: 0000000000000000 RCX: 00007fee0817c718 [ 2.829034] RDX: 00007fffeba5e188 RSI: 00007fffeba5e178 RDI: 0000000000000001 [ 2.829257] RBP: 00007fffeba5e080 R08: 0000000000000000 R09: 00007fee08193c00 [ 2.829482] R10: 0000000000000009 R11: 0000000000000000 R12: 000055e2c76d2040 [ 2.829727] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 2.829964] CR2: 0000000000000020 [ 2.830149] ---[ end trace ceed83d8c68a1bf1 ]--- ``` Cc: # v4.11+ Fixes: 64e90a8acb85 ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()") BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199795 Reported-by: Tony Vroon Reported-by: Sergey Kvachonok Tested-by: Sergei Trofimovich Signed-off-by: Luis Chamberlain Link: https://lore.kernel.org/r/20200416162859.26518-1-mcgrof@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/coredump.c | 8 ++++++++ kernel/umh.c | 5 +++++ 2 files changed, 13 insertions(+) diff --git a/fs/coredump.c b/fs/coredump.c index 408418e6aa131..478a0d810136a 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -788,6 +788,14 @@ void do_coredump(const kernel_siginfo_t *siginfo) if (displaced) put_files_struct(displaced); if (!dump_interrupted()) { + /* + * umh disabled with CONFIG_STATIC_USERMODEHELPER_PATH="" would + * have this set to NULL. + */ + if (!cprm.file) { + pr_info("Core dump to |%s disabled\n", cn.corename); + goto close_fail; + } file_start_write(cprm.file); core_dumped = binfmt->core_dump(&cprm); file_end_write(cprm.file); diff --git a/kernel/umh.c b/kernel/umh.c index 7f255b5a8845a..11bf5eea474c5 100644 --- a/kernel/umh.c +++ b/kernel/umh.c @@ -544,6 +544,11 @@ EXPORT_SYMBOL_GPL(fork_usermode_blob); * Runs a user-space application. The application is started * asynchronously if wait is not set, and runs as a child of system workqueues. * (ie. it runs with full root capabilities and optimized affinity). + * + * Note: successful return value does not guarantee the helper was called at + * all. You can't rely on sub_info->{init,cleanup} being called even for + * UMH_WAIT_* wait modes as STATIC_USERMODEHELPER_PATH="" turns all helpers + * into a successful no-op. */ int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait) { From 00b247557858bc0651a646710d90aba186bfeed4 Mon Sep 17 00:00:00 2001 From: Saravana Kannan Date: Mon, 30 Mar 2020 19:28:32 -0700 Subject: [PATCH 4/9] driver core: Fix handling of fw_devlink=permissive When commit 8375e74f2bca ("driver core: Add fw_devlink kernel commandline option") added fw_devlink, it didn't implement "permissive" mode correctly. That commit got the device links flags correct to make sure unprobed suppliers don't block the probing of a consumer. However, if a consumer is waiting for mandatory suppliers to register, that could still block a consumer from probing. This commit fixes that by making sure in permissive mode, all suppliers to a consumer are treated as a optional suppliers. So, even if a consumer is waiting for suppliers to register and link itself (using the DL_FLAG_SYNC_STATE_ONLY flag) to the supplier, the consumer is never blocked from probing. Fixes: 8375e74f2bca ("driver core: Add fw_devlink kernel commandline option") Reported-by: Marek Szyprowski Signed-off-by: Saravana Kannan Tested-by: Marek Szyprowski Link: https://lore.kernel.org/r/20200331022832.209618-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 139cdf7e73271..073045cb214e8 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2370,6 +2370,11 @@ u32 fw_devlink_get_flags(void) return fw_devlink_flags; } +static bool fw_devlink_is_permissive(void) +{ + return fw_devlink_flags == DL_FLAG_SYNC_STATE_ONLY; +} + /** * device_add - add device to device hierarchy. * @dev: device. @@ -2524,7 +2529,7 @@ int device_add(struct device *dev) if (fw_devlink_flags && is_fwnode_dev && fwnode_has_op(dev->fwnode, add_links)) { fw_ret = fwnode_call_int_op(dev->fwnode, add_links, dev); - if (fw_ret == -ENODEV) + if (fw_ret == -ENODEV && !fw_devlink_is_permissive()) device_link_wait_for_mandatory_supplier(dev); else if (fw_ret) device_link_wait_for_optional_supplier(dev); From 7706b0a76a9697021e2bf395f3f065c18f51043d Mon Sep 17 00:00:00 2001 From: James Hilliard Date: Sat, 11 Apr 2020 13:02:41 -0600 Subject: [PATCH 5/9] component: Silence bind error on -EPROBE_DEFER If a component fails to bind due to -EPROBE_DEFER we should not log an error as this is not a real failure. Fixes messages like: vc4-drm soc:gpu: failed to bind 3f902000.hdmi (ops vc4_hdmi_ops): -517 vc4-drm soc:gpu: master bind failed: -517 Signed-off-by: James Hilliard Link: https://lore.kernel.org/r/20200411190241.89404-1-james.hilliard1@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/component.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/base/component.c b/drivers/base/component.c index e977041047845..dcfbe7251dc43 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -256,7 +256,8 @@ static int try_to_bring_up_master(struct master *master, ret = master->ops->bind(master->dev); if (ret < 0) { devres_release_group(master->dev, NULL); - dev_info(master->dev, "master bind failed: %d\n", ret); + if (ret != -EPROBE_DEFER) + dev_info(master->dev, "master bind failed: %d\n", ret); return ret; } @@ -611,8 +612,9 @@ static int component_bind(struct component *component, struct master *master, devres_release_group(component->dev, NULL); devres_release_group(master->dev, NULL); - dev_err(master->dev, "failed to bind %s (ops %ps): %d\n", - dev_name(component->dev), component->ops, ret); + if (ret != -EPROBE_DEFER) + dev_err(master->dev, "failed to bind %s (ops %ps): %d\n", + dev_name(component->dev), component->ops, ret); } return ret; From ce68929f07de0780c1afbbeef9aa6cf3550163d6 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 22 Apr 2020 20:32:43 +0000 Subject: [PATCH 6/9] driver core: Revert default driver_deferred_probe_timeout value to 0 This patch addresses a regression in 5.7-rc1+ In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic"), we both cleaned up the logic and also set the default driver_deferred_probe_timeout value to 30 seconds to allow for drivers that are missing dependencies to have some time so that the dependency may be loaded from userland after initcalls_done is set. However, Yoshihiro Shimoda reported that on his device that expects to have unmet dependencies (due to "optional links" in its devicetree), was failing to mount the NFS root. In digging further, it seemed the problem was that while the device properly probes after waiting 30 seconds for any missing modules to load, the ip_auto_config() had already failed, resulting in NFS to fail. This was due to ip_auto_config() calling wait_for_device_probe() which doesn't wait for the driver_deferred_probe_timeout to fire. Fixing that issue is possible, but could also introduce 30 second delays in bootups for users who don't have any missing dependencies, which is not ideal. So I think the best solution to avoid any regressions is to revert back to a default timeout value of zero, and allow systems that need to utilize the timeout in order for userland to load any modules that supply misisng dependencies in the dts to specify the timeout length via the exiting documented boot argument. Thanks to Geert for chasing down that ip_auto_config was why NFS was failing in this case! Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: Hideaki YOSHIFUJI Cc: Jakub Kicinski Cc: Rafael J. Wysocki Cc: Rob Herring Cc: Geert Uytterhoeven Cc: Yoshihiro Shimoda Cc: Robin Murphy Cc: Andy Shevchenko Cc: Sudeep Holla Cc: Andy Shevchenko Cc: Naresh Kamboju Cc: Basil Eljuse Cc: Ferry Toth Cc: Arnd Bergmann Cc: Anders Roxell Reported-by: Yoshihiro Shimoda Tested-by: Yoshihiro Shimoda Tested-by: Geert Uytterhoeven Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz Link: https://lore.kernel.org/r/20200422203245.83244-2-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 06ec0e851fa16..908ae4d7805e6 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -224,16 +224,7 @@ static int deferred_devs_show(struct seq_file *s, void *data) } DEFINE_SHOW_ATTRIBUTE(deferred_devs); -#ifdef CONFIG_MODULES -/* - * In the case of modules, set the default probe timeout to - * 30 seconds to give userland some time to load needed modules - */ -int driver_deferred_probe_timeout = 30; -#else -/* In the case of !modules, no probe timeout needed */ -int driver_deferred_probe_timeout = -1; -#endif +int driver_deferred_probe_timeout; EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout); static int __init deferred_probe_timeout_setup(char *str) @@ -266,7 +257,7 @@ int driver_deferred_probe_check_state(struct device *dev) return -ENODEV; } - if (!driver_deferred_probe_timeout) { + if (!driver_deferred_probe_timeout && initcalls_done) { dev_WARN(dev, "deferred probe timeout, ignoring dependency"); return -ETIMEDOUT; } From 4ccc03e28ec309173f434fa38b48b6ad65ff5d1b Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 22 Apr 2020 20:32:44 +0000 Subject: [PATCH 7/9] driver core: Use dev_warn() instead of dev_WARN() for deferred_probe_timeout warnings In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") and following changes the logic was changes slightly so that if there is no driver to match whats found in the dtb, we wait the sepcified seconds for modules to be loaded by userland, and then timeout, where as previously we'd print "ignoring dependency for device, assuming no driver" and immediately return -ENODEV after initcall_done. However, in the timeout case (which previously existed but was practicaly un-used without a boot argument), the timeout message uses dev_WARN(). This means folks are now seeing a big backtrace in their boot logs if there a entry in their dts that doesn't have a driver. To fix this, lets use dev_warn(), instead of dev_WARN() to match the previous error path. Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: Hideaki YOSHIFUJI Cc: Jakub Kicinski Cc: Rafael J. Wysocki Cc: Rob Herring Cc: Geert Uytterhoeven Cc: Yoshihiro Shimoda Cc: Robin Murphy Cc: Andy Shevchenko Cc: Sudeep Holla Cc: Andy Shevchenko Cc: Naresh Kamboju Cc: Basil Eljuse Cc: Ferry Toth Cc: Arnd Bergmann Cc: Anders Roxell Cc: linux-pm@vger.kernel.org Reviewed-by: Yoshihiro Shimoda Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz Link: https://lore.kernel.org/r/20200422203245.83244-3-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 908ae4d7805e6..9c88afa5c74a6 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -258,7 +258,7 @@ int driver_deferred_probe_check_state(struct device *dev) } if (!driver_deferred_probe_timeout && initcalls_done) { - dev_WARN(dev, "deferred probe timeout, ignoring dependency"); + dev_warn(dev, "deferred probe timeout, ignoring dependency"); return -ETIMEDOUT; } From 35a672363ab3e8dfe4ebcadb4dd0b2d06bb85ebe Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 22 Apr 2020 20:32:45 +0000 Subject: [PATCH 8/9] driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires In commit c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic"), we set the default driver_deferred_probe_timeout value to 30 seconds to allow for drivers that are missing dependencies to have some time so that the dependency may be loaded from userland after initcalls_done is set. However, Yoshihiro Shimoda reported that on his device that expects to have unmet dependencies (due to "optional links" in its devicetree), was failing to mount the NFS root. In digging further, it seemed the problem was that while the device properly probes after waiting 30 seconds for any missing modules to load, the ip_auto_config() had already failed, resulting in NFS to fail. This was due to ip_auto_config() calling wait_for_device_probe() which doesn't wait for the driver_deferred_probe_timeout to fire. This patch tries to fix the issue by creating a waitqueue for the driver_deferred_probe_timeout, and calling wait_event() to make sure driver_deferred_probe_timeout is zero in wait_for_device_probe() to make sure all the probing is finished. The downside to this solution is that kernel functionality that uses wait_for_device_probe(), will block until the driver_deferred_probe_timeout fires, regardless of if there is any missing dependencies. However, the previous patch reverts the default timeout value to zero, so this side-effect will only affect users who specify a driver_deferred_probe_timeout= value as a boot argument, where the additional delay would be beneficial to allow modules to load later during boot. Thanks to Geert for chasing down that ip_auto_config was why NFS was failing in this case! Cc: "David S. Miller" Cc: Alexey Kuznetsov Cc: Hideaki YOSHIFUJI Cc: Jakub Kicinski Cc: Rafael J. Wysocki Cc: Rob Herring Cc: Geert Uytterhoeven Cc: Yoshihiro Shimoda Cc: Robin Murphy Cc: Andy Shevchenko Cc: Sudeep Holla Cc: Andy Shevchenko Cc: Naresh Kamboju Cc: Basil Eljuse Cc: Ferry Toth Cc: Arnd Bergmann Cc: Anders Roxell Cc: linux-pm@vger.kernel.org Reported-by: Yoshihiro Shimoda Tested-by: Geert Uytterhoeven Tested-by: Yoshihiro Shimoda Fixes: c8c43cee29f6 ("driver core: Fix driver_deferred_probe_check_state() logic") Signed-off-by: John Stultz Link: https://lore.kernel.org/r/20200422203245.83244-4-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 9c88afa5c74a6..94037be7f5d75 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -226,6 +226,7 @@ DEFINE_SHOW_ATTRIBUTE(deferred_devs); int driver_deferred_probe_timeout; EXPORT_SYMBOL_GPL(driver_deferred_probe_timeout); +static DECLARE_WAIT_QUEUE_HEAD(probe_timeout_waitqueue); static int __init deferred_probe_timeout_setup(char *str) { @@ -275,6 +276,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work) list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe) dev_info(private->device, "deferred probe pending"); + wake_up(&probe_timeout_waitqueue); } static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func); @@ -649,6 +651,9 @@ int driver_probe_done(void) */ void wait_for_device_probe(void) { + /* wait for probe timeout */ + wait_event(probe_timeout_waitqueue, !driver_deferred_probe_timeout); + /* wait for the deferred probe workqueue to finish */ flush_work(&deferred_probe_work); From 2a15483b401c0b07e44b43b95414e36f32c02f32 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Wed, 29 Apr 2020 17:23:49 +0000 Subject: [PATCH 9/9] regulator: Revert "Use driver_deferred_probe_timeout for regulator_init_complete_work" This reverts commit dca0b44957e5 ("regulator: Use driver_deferred_probe_timeout for regulator_init_complete_work"), as we ended up reverting the default deferred_probe_timeout value back to zero, to preserve behavior with 5.6 we need to decouple the regulator timeout which was previously 30 seconds. This avoids breaking some systems that depend on the regulator timeout but don't require the deferred probe timeout. Cc: linux-pm@vger.kernel.org Cc: Linus Walleij Cc: Thierry Reding Cc: Liam Girdwood Cc: Bjorn Andersson Cc: Saravana Kannan Cc: Todd Kjos Cc: Len Brown Cc: Pavel Machek Cc: Ulf Hansson Cc: Kevin Hilman Cc: "Rafael J. Wysocki" Cc: Rob Herring Reported-by: Marek Szyprowski Suggested-by: Mark Brown Signed-off-by: John Stultz Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20200429172349.55979-1-john.stultz@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/regulator/core.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index c340505150b68..7486f6e4e613c 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -5754,10 +5754,6 @@ static DECLARE_DELAYED_WORK(regulator_init_complete_work, static int __init regulator_init_complete(void) { - int delay = driver_deferred_probe_timeout; - - if (delay < 0) - delay = 0; /* * Since DT doesn't provide an idiomatic mechanism for * enabling full constraints and since it's much more natural @@ -5768,17 +5764,18 @@ static int __init regulator_init_complete(void) has_full_constraints = true; /* - * If driver_deferred_probe_timeout is set, we punt - * completion for that many seconds since systems like - * distros will load many drivers from userspace so consumers - * might not always be ready yet, this is particularly an - * issue with laptops where this might bounce the display off - * then on. Ideally we'd get a notification from userspace - * when this happens but we don't so just wait a bit and hope - * we waited long enough. It'd be better if we'd only do - * this on systems that need it. + * We punt completion for an arbitrary amount of time since + * systems like distros will load many drivers from userspace + * so consumers might not always be ready yet, this is + * particularly an issue with laptops where this might bounce + * the display off then on. Ideally we'd get a notification + * from userspace when this happens but we don't so just wait + * a bit and hope we waited long enough. It'd be better if + * we'd only do this on systems that need it, and a kernel + * command line option might be useful. */ - schedule_delayed_work(®ulator_init_complete_work, delay * HZ); + schedule_delayed_work(®ulator_init_complete_work, + msecs_to_jiffies(30000)); return 0; }