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  1. 15 5月, 2019 1 次提交
  3. 20 4月, 2019 2 次提交
    • K
      mm: hide incomplete nr_indirectly_reclaimable in sysfs · 9e91db59
      由 Konstantin Khlebnikov 提交于 
      In upstream branch this fixed by commit b29940c1abd7 ("mm: rename and
change semantics of nr_indirectly_reclaimable_bytes").

This fixes /sys/devices/system/node/node*/vmstat format:

...
nr_dirtied 6613155
nr_written 5796802
 11089216
...

Cc: <stable@vger.kernel.org> # 4.19.y
Fixes: 7aaf7727 ("mm: don't show nr_indirectly_reclaimable in /proc/vmstat")
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9e91db59
    • J
      PM / Domains: Avoid a potential deadlock · b63df738
      由 Jiada Wang 提交于 
      [ Upstream commit 2071ac985d37efe496782c34318dbead93beb02f ]

Lockdep warns that prepare_lock and genpd->mlock can cause a deadlock
the deadlock scenario is like following:
First thread is probing cs2000
cs2000_probe()
  clk_register()
    __clk_core_init()
      clk_prepare_lock()                            ----> acquires prepare_lock
        cs2000_recalc_rate()
          i2c_smbus_read_byte_data()
            rcar_i2c_master_xfer()
              dma_request_chan()
                rcar_dmac_of_xlate()
                  rcar_dmac_alloc_chan_resources()
                    pm_runtime_get_sync()
                      __pm_runtime_resume()
                        rpm_resume()
                          rpm_callback()
                            genpd_runtime_resume()   ----> acquires genpd->mlock

Second thread is attaching any device to the same PM domain
genpd_add_device()
  genpd_lock()                                       ----> acquires genpd->mlock
    cpg_mssr_attach_dev()
      of_clk_get_from_provider()
        __of_clk_get_from_provider()
          __clk_create_clk()
            clk_prepare_lock()                       ----> acquires prepare_lock

Since currently no PM provider access genpd's critical section
in .attach_dev, and .detach_dev callbacks, so there is no need to protect
these two callbacks with genpd->mlock.
This patch avoids a potential deadlock by moving out .attach_dev and .detach_dev
from genpd->mlock, so that genpd->mlock won't be held when prepare_lock is acquired
in .attach_dev and .detach_dev
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      b63df738
  5. 24 3月, 2019 1 次提交
    • V
      PM / wakeup: Rework wakeup source timer cancellation · cd738246
      由 Viresh Kumar 提交于 
      commit 1fad17fb1bbcd73159c2b992668a6957ecc5af8a upstream.

If wakeup_source_add() is called right after wakeup_source_remove()
for the same wakeup source, timer_setup() may be called for a
potentially scheduled timer which is incorrect.

To avoid that, move the wakeup source timer cancellation from
wakeup_source_drop() to wakeup_source_remove().

Moreover, make wakeup_source_remove() clear the timer function after
canceling the timer to let wakeup_source_not_registered() treat
unregistered wakeup sources in the same way as the ones that have
never been registered.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
[ rjw: Subject, changelog, merged two patches together ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cd738246
  7. 14 3月, 2019 1 次提交
    • G
      driver core: Postpone DMA tear-down until after devres release · 7053a6fa
      由 Geert Uytterhoeven 提交于 
      commit 376991db4b6464e906d699ef07681e2ffa8ab08c upstream.

When unbinding the (IOMMU-enabled) R-Car SATA device on Salvator-XS
(R-Car H3 ES2.0), in preparation of rebinding against vfio-platform for
device pass-through for virtualization:

    echo ee300000.sata > /sys/bus/platform/drivers/sata_rcar/unbind

the kernel crashes with:

    Unable to handle kernel paging request at virtual address ffffffbf029ffffc
    Mem abort info:
      ESR = 0x96000006
      Exception class = DABT (current EL), IL = 32 bits
      SET = 0, FnV = 0
      EA = 0, S1PTW = 0
    Data abort info:
      ISV = 0, ISS = 0x00000006
      CM = 0, WnR = 0
    swapper pgtable: 4k pages, 39-bit VAs, pgdp = 000000007e8c586c
    [ffffffbf029ffffc] pgd=000000073bfc6003, pud=000000073bfc6003, pmd=0000000000000000
    Internal error: Oops: 96000006 [#1] SMP
    Modules linked in:
    CPU: 0 PID: 1098 Comm: bash Not tainted 5.0.0-rc5-salvator-x-00452-g37596f884f4318ef #287
    Hardware name: Renesas Salvator-X 2nd version board based on r8a7795 ES2.0+ (DT)
    pstate: 60400005 (nZCv daif +PAN -UAO)
    pc : __free_pages+0x8/0x58
    lr : __dma_direct_free_pages+0x50/0x5c
    sp : ffffff801268baa0
    x29: ffffff801268baa0 x28: 0000000000000000
    x27: ffffffc6f9c60bf0 x26: ffffffc6f9c60bf0
    x25: ffffffc6f9c60810 x24: 0000000000000000
    x23: 00000000fffff000 x22: ffffff8012145000
    x21: 0000000000000800 x20: ffffffbf029fffc8
    x19: 0000000000000000 x18: ffffffc6f86c42c8
    x17: 0000000000000000 x16: 0000000000000070
    x15: 0000000000000003 x14: 0000000000000000
    x13: ffffff801103d7f8 x12: 0000000000000028
    x11: ffffff8011117604 x10: 0000000000009ad8
    x9 : ffffff80110126d0 x8 : ffffffc6f7563000
    x7 : 6b6b6b6b6b6b6b6b x6 : 0000000000000018
    x5 : ffffff8011cf3cc8 x4 : 0000000000004000
    x3 : 0000000000080000 x2 : 0000000000000001
    x1 : 0000000000000000 x0 : ffffffbf029fffc8
    Process bash (pid: 1098, stack limit = 0x00000000c38e3e32)
    Call trace:
     __free_pages+0x8/0x58
     __dma_direct_free_pages+0x50/0x5c
     arch_dma_free+0x1c/0x98
     dma_direct_free+0x14/0x24
     dma_free_attrs+0x9c/0xdc
     dmam_release+0x18/0x20
     release_nodes+0x25c/0x28c
     devres_release_all+0x48/0x4c
     device_release_driver_internal+0x184/0x1f0
     device_release_driver+0x14/0x1c
     unbind_store+0x70/0xb8
     drv_attr_store+0x24/0x34
     sysfs_kf_write+0x4c/0x64
     kernfs_fop_write+0x154/0x1c4
     __vfs_write+0x34/0x164
     vfs_write+0xb4/0x16c
     ksys_write+0x5c/0xbc
     __arm64_sys_write+0x14/0x1c
     el0_svc_common+0x98/0x114
     el0_svc_handler+0x1c/0x24
     el0_svc+0x8/0xc
    Code: d51b4234 17fffffa a9bf7bfd 910003fd (b9403404)
    ---[ end trace 8c564cdd3a1a840f ]---

While I've bisected this to commit e8e683ae9a736407 ("iommu/of: Fix
probe-deferral"), and reverting that commit on post-v5.0-rc4 kernels
does fix the problem, this turned out to be a red herring.

On arm64, arch_teardown_dma_ops() resets dev->dma_ops to NULL.
Hence if a driver has used a managed DMA allocation API, the allocated
DMA memory will be freed using the direct DMA ops, while it may have
been allocated using a custom DMA ops (iommu_dma_ops in this case).

Fix this by reversing the order of the calls to devres_release_all() and
arch_teardown_dma_ops().
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
[rm: backport for 4.12-4.19 - kernels before 5.0 will not see
 the crash above, but may get silent memory corruption instead]
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7053a6fa
  9. 13 2月, 2019 4 次提交
  11. 26 1月, 2019 1 次提交
    • D
      sysfs: Disable lockdep for driver bind/unbind files · a13daf03
      由 Daniel Vetter 提交于 
      [ Upstream commit 4f4b374332ec0ae9c738ff8ec9bed5cd97ff9adc ]

This is the much more correct fix for my earlier attempt at:

https://lkml.org/lkml/2018/12/10/118

Short recap:

- There's not actually a locking issue, it's just lockdep being a bit
  too eager to complain about a possible deadlock.

- Contrary to what I claimed the real problem is recursion on
  kn->count. Greg pointed me at sysfs_break_active_protection(), used
  by the scsi subsystem to allow a sysfs file to unbind itself. That
  would be a real deadlock, which isn't what's happening here. Also,
  breaking the active protection means we'd need to manually handle
  all the lifetime fun.

- With Rafael we discussed the task_work approach, which kinda works,
  but has two downsides: It's a functional change for a lockdep
  annotation issue, and it won't work for the bind file (which needs
  to get the errno from the driver load function back to userspace).

- Greg also asked why this never showed up: To hit this you need to
  unregister a 2nd driver from the unload code of your first driver. I
  guess only gpus do that. The bug has always been there, but only
  with a recent patch series did we add more locks so that lockdep
  built a chain from unbinding the snd-hda driver to the
  acpi_video_unregister call.

Full lockdep splat:

[12301.898799] ============================================
[12301.898805] WARNING: possible recursive locking detected
[12301.898811] 4.20.0-rc7+ #84 Not tainted
[12301.898815] --------------------------------------------
[12301.898821] bash/5297 is trying to acquire lock:
[12301.898826] 00000000f61c6093 (kn->count#39){++++}, at: kernfs_remove_by_name_ns+0x3b/0x80
[12301.898841] but task is already holding lock:
[12301.898847] 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190
[12301.898856] other info that might help us debug this:
[12301.898862]  Possible unsafe locking scenario:
[12301.898867]        CPU0
[12301.898870]        ----
[12301.898874]   lock(kn->count#39);
[12301.898879]   lock(kn->count#39);
[12301.898883] *** DEADLOCK ***
[12301.898891]  May be due to missing lock nesting notation
[12301.898899] 5 locks held by bash/5297:
[12301.898903]  #0: 00000000cd800e54 (sb_writers#4){.+.+}, at: vfs_write+0x17f/0x1b0
[12301.898915]  #1: 000000000465e7c2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xd3/0x190
[12301.898925]  #2: 000000005f634021 (kn->count#39){++++}, at: kernfs_fop_write+0xdc/0x190
[12301.898936]  #3: 00000000414ef7ac (&dev->mutex){....}, at: device_release_driver_internal+0x34/0x240
[12301.898950]  #4: 000000003218fbdf (register_count_mutex){+.+.}, at: acpi_video_unregister+0xe/0x40
[12301.898960] stack backtrace:
[12301.898968] CPU: 1 PID: 5297 Comm: bash Not tainted 4.20.0-rc7+ #84
[12301.898974] Hardware name: Hewlett-Packard HP EliteBook 8460p/161C, BIOS 68SCF Ver. F.01 03/11/2011
[12301.898982] Call Trace:
[12301.898989]  dump_stack+0x67/0x9b
[12301.898997]  __lock_acquire+0x6ad/0x1410
[12301.899003]  ? kernfs_remove_by_name_ns+0x3b/0x80
[12301.899010]  ? find_held_lock+0x2d/0x90
[12301.899017]  ? mutex_spin_on_owner+0xe4/0x150
[12301.899023]  ? find_held_lock+0x2d/0x90
[12301.899030]  ? lock_acquire+0x90/0x180
[12301.899036]  lock_acquire+0x90/0x180
[12301.899042]  ? kernfs_remove_by_name_ns+0x3b/0x80
[12301.899049]  __kernfs_remove+0x296/0x310
[12301.899055]  ? kernfs_remove_by_name_ns+0x3b/0x80
[12301.899060]  ? kernfs_name_hash+0xd/0x80
[12301.899066]  ? kernfs_find_ns+0x6c/0x100
[12301.899073]  kernfs_remove_by_name_ns+0x3b/0x80
[12301.899080]  bus_remove_driver+0x92/0xa0
[12301.899085]  acpi_video_unregister+0x24/0x40
[12301.899127]  i915_driver_unload+0x42/0x130 [i915]
[12301.899160]  i915_pci_remove+0x19/0x30 [i915]
[12301.899169]  pci_device_remove+0x36/0xb0
[12301.899176]  device_release_driver_internal+0x185/0x240
[12301.899183]  unbind_store+0xaf/0x180
[12301.899189]  kernfs_fop_write+0x104/0x190
[12301.899195]  __vfs_write+0x31/0x180
[12301.899203]  ? rcu_read_lock_sched_held+0x6f/0x80
[12301.899209]  ? rcu_sync_lockdep_assert+0x29/0x50
[12301.899216]  ? __sb_start_write+0x13c/0x1a0
[12301.899221]  ? vfs_write+0x17f/0x1b0
[12301.899227]  vfs_write+0xb9/0x1b0
[12301.899233]  ksys_write+0x50/0xc0
[12301.899239]  do_syscall_64+0x4b/0x180
[12301.899247]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[12301.899253] RIP: 0033:0x7f452ac7f7a4
[12301.899259] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 80 00 00 00 00 8b 05 aa f0 2c 00 48 63 ff 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 55 53 48 89 d5 48 89 f3 48 83
[12301.899273] RSP: 002b:00007ffceafa6918 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[12301.899282] RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007f452ac7f7a4
[12301.899288] RDX: 000000000000000d RSI: 00005612a1abf7c0 RDI: 0000000000000001
[12301.899295] RBP: 00005612a1abf7c0 R08: 000000000000000a R09: 00005612a1c46730
[12301.899301] R10: 000000000000000a R11: 0000000000000246 R12: 000000000000000d
[12301.899308] R13: 0000000000000001 R14: 00007f452af4a740 R15: 000000000000000d

Looking around I've noticed that usb and i2c already handle similar
recursion problems, where a sysfs file can unbind the same type of
sysfs somewhere else in the hierarchy. Relevant commits are:

commit 356c05d5
Author: Alan Stern <stern@rowland.harvard.edu>
Date:   Mon May 14 13:30:03 2012 -0400

    sysfs: get rid of some lockdep false positives

commit e9b526fe
Author: Alexander Sverdlin <alexander.sverdlin@nsn.com>
Date:   Fri May 17 14:56:35 2013 +0200

    i2c: suppress lockdep warning on delete_device

Implement the same trick for driver bind/unbind.

v2: Put the macro into bus.c (Greg).
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Ramalingam C <ramalingam.c@intel.com>
Cc: Arend van Spriel <aspriel@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Vivek Gautam <vivek.gautam@codeaurora.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      a13daf03
  13. 13 1月, 2019 1 次提交
  15. 10 1月, 2019 1 次提交
    • M
      platform-msi: Free descriptors in platform_msi_domain_free() · 6c56e89e
      由 Miquel Raynal 提交于 
      commit 81b1e6e6a8590a19257e37a1633bec098d499c57 upstream.

Since the addition of platform MSI support, there were two helpers
supposed to allocate/free IRQs for a device:

    platform_msi_domain_alloc_irqs()
    platform_msi_domain_free_irqs()

In these helpers, IRQ descriptors are allocated in the "alloc" routine
while they are freed in the "free" one.

Later, two other helpers have been added to handle IRQ domains on top
of MSI domains:

    platform_msi_domain_alloc()
    platform_msi_domain_free()

Seen from the outside, the logic is pretty close with the former
helpers and people used it with the same logic as before: a
platform_msi_domain_alloc() call should be balanced with a
platform_msi_domain_free() call. While this is probably what was
intended to do, the platform_msi_domain_free() does not remove/free
the IRQ descriptor(s) created/inserted in
platform_msi_domain_alloc().

One effect of such situation is that removing a module that requested
an IRQ will let one orphaned IRQ descriptor (with an allocated MSI
entry) in the device descriptors list. Next time the module will be
inserted back, one will observe that the allocation will happen twice
in the MSI domain, one time for the remaining descriptor, one time for
the new one. It also has the side effect to quickly overshoot the
maximum number of allocated MSI and then prevent any module requesting
an interrupt in the same domain to be inserted anymore.

This situation has been met with loops of insertion/removal of the
mvpp2.ko module (requesting 15 MSIs each time).

Fixes: 552c494a ("platform-msi: Allow creation of a MSI-based stacked irq domain")
Cc: stable@vger.kernel.org
Signed-off-by: NMiquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6c56e89e
  17. 05 10月, 2018 1 次提交
  19. 30 9月, 2018 1 次提交
  21. 12 9月, 2018 1 次提交
    • R
      firmware: Fix security issue with request_firmware_into_buf() · 422b3db2
      由 Rishabh Bhatnagar 提交于 
      When calling request_firmware_into_buf() with the FW_OPT_NOCACHE flag
it is expected that firmware is loaded into buffer from memory.
But inside alloc_lookup_fw_priv every new firmware that is loaded is
added to the firmware cache (fwc) list head. So if any driver requests
a firmware that is already loaded the code iterates over the above
mentioned list and it can end up giving a pointer to other device driver's
firmware buffer.
Also the existing copy may either be modified by drivers, remote processors
or even freed. This causes a potential security issue with batched requests
when using request_firmware_into_buf.

Fix alloc_lookup_fw_priv to not add to the fwc head list if FW_OPT_NOCACHE
is set, and also don't do the lookup in the list.

Fixes: 0e742e92 ("firmware: provide infrastructure to make fw caching optional")
[mcgrof: broken since feature introduction on v4.8]

Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: NVikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: NRishabh Bhatnagar <rishabhb@codeaurora.org>
Signed-off-by: NLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      422b3db2
  23. 05 9月, 2018 1 次提交
    • M
      memory_hotplug: fix kernel_panic on offline page processing · 4e8346d0
      由 Mikhail Zaslonko 提交于 
      Within show_valid_zones() the function test_pages_in_a_zone() should be
called for online memory blocks only.

Otherwise it might lead to the VM_BUG_ON due to uninitialized struct
pages (when CONFIG_DEBUG_VM_PGFLAGS kernel option is set):

 page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
 ------------[ cut here ]------------
 Call Trace:
 ([<000000000038f91e>] test_pages_in_a_zone+0xe6/0x168)
  [<0000000000923472>] show_valid_zones+0x5a/0x1a8
  [<0000000000900284>] dev_attr_show+0x3c/0x78
  [<000000000046f6f0>] sysfs_kf_seq_show+0xd0/0x150
  [<00000000003ef662>] seq_read+0x212/0x4b8
  [<00000000003bf202>] __vfs_read+0x3a/0x178
  [<00000000003bf3ca>] vfs_read+0x8a/0x148
  [<00000000003bfa3a>] ksys_read+0x62/0xb8
  [<0000000000bc2220>] system_call+0xdc/0x2d8

That VM_BUG_ON was triggered by the page poisoning introduced in
mm/sparse.c with the git commit d0dc12e8 ("mm/memory_hotplug:
optimize memory hotplug").

With the same commit the new 'nid' field has been added to the struct
memory_block in order to store and later on derive the node id for
offline pages (instead of accessing struct page which might be
uninitialized).  But one reference to nid in show_valid_zones() function
has been overlooked.  Fixed with current commit.  Also, nr_pages will
not be used any more after test_pages_in_a_zone() call, do not update
it.

Link: http://lkml.kernel.org/r/20180828090539.41491-1-zaslonko@linux.ibm.com
Fixes: d0dc12e8 ("mm/memory_hotplug: optimize memory hotplug")
Signed-off-by: NMikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NPavel Tatashin <pavel.tatashin@microsoft.com>
Cc: <stable@vger.kernel.org>	[4.17+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4e8346d0
  25. 24 8月, 2018 1 次提交
  27. 18 8月, 2018 4 次提交
  29. 09 8月, 2018 1 次提交
    • C
      regmap: Add regmap_noinc_read API · 74fe7b55
      由 Crestez Dan Leonard 提交于 
      The regmap API usually assumes that bulk read operations will read a
range of registers but some I2C/SPI devices have certain registers for
which a such a read operation will return data from an internal FIFO
instead. Add an explicit API to support bulk read without range semantics.

Some linux drivers use regmap_bulk_read or regmap_raw_read for such
registers, for example mpu6050 or bmi150 from IIO. This only happens to
work because when caching is disabled a single regmap read op will map
to a single bus read op (as desired). This breaks if caching is enabled and
reg+1 happens to be a cacheable register.

Without regmap support refactoring a driver to enable regmap caching
requires separate I2C and SPI paths. This is exactly what regmap is
supposed to help avoid.
Suggested-by: NJonathan Cameron <jic23@kernel.org>
Signed-off-by: NCrestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: NStefan Popa <stefan.popa@analog.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
      74fe7b55
  31. 24 7月, 2018 1 次提交
  33. 21 7月, 2018 3 次提交
  35. 18 7月, 2018 1 次提交
    • A
      regmap: add SCCB support · bcf7eac3
      由 Akinobu Mita 提交于 
      This adds Serial Camera Control Bus (SCCB) support for regmap API that
is intended to be used by some of Omnivision sensor drivers.

The ov772x and ov9650 drivers are going to use this SCCB regmap API.

The ov772x driver was previously only worked with the i2c controller
drivers that support I2C_FUNC_PROTOCOL_MANGLING, because the ov772x
device doesn't support repeated starts.  After commit 0b964d18
("media: ov772x: allow i2c controllers without
I2C_FUNC_PROTOCOL_MANGLING"), reading ov772x register is replaced with
issuing two separated i2c messages in order to avoid repeated start.
Using this SCCB regmap hides the implementation detail.

The ov9650 driver also issues two separated i2c messages to read the
registers as the device doesn't support repeated start.  So it can
make use of this SCCB regmap.

Cc: Mark Brown <broonie@kernel.org>
Cc: Peter Rosin <peda@axentia.se>
Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
      bcf7eac3
  37. 17 7月, 2018 1 次提交
  39. 16 7月, 2018 2 次提交
    • B
      drivers: core: Remove glue dirs from sysfs earlier · 726e4109
      由 Benjamin Herrenschmidt 提交于 
      For devices with a class, we create a "glue" directory between
the parent device and the new device with the class name.

This directory is never "explicitely" removed when empty however,
this is left to the implicit sysfs removal done by kobject_release()
when the object loses its last reference via kobject_put().

This is problematic because as long as it's not been removed from
sysfs, it is still present in the class kset and in sysfs directory
structure.

The presence in the class kset exposes a use after free bug fixed
by the previous patch, but the presence in sysfs means that until
the kobject is released, which can take a while (especially with
kobject debugging), any attempt at re-creating such as binding a
new device for that class/parent pair, will result in a sysfs
duplicate file name error.

This fixes it by instead doing an explicit kobject_del() when
the glue dir is empty, by keeping track of the number of
child devices of the gluedir.

This is made easy by the fact that all glue dir operations are
done with a global mutex, and there's already a function
(cleanup_glue_dir) called in all the right places taking that
mutex that can be enhanced for this. It appears that this was
in fact the intent of the function, but the implementation was
wrong.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      726e4109
    • S
      driver core: remove unnecessary function extern declare · 46d3a037
      由 Shaokun Zhang 提交于 
      device_private_init is called only in core.c, extern declare is
unnecessary and make it static.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: NShaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      46d3a037
  41. 11 7月, 2018 1 次提交
  43. 10 7月, 2018 3 次提交
    • R
      driver core: Partially revert "driver core: correct device's shutdown order" · 722e5f2b
      由 Rafael J. Wysocki 提交于 
      Commit 52cdbdd4 (driver core: correct device's shutdown order)
introduced a regression by breaking device shutdown on some systems.

Namely, the devices_kset_move_last() call in really_probe() added by
that commit is a mistake as it may cause parents to follow children
in the devices_kset list which then causes shutdown to fail.  For
example, if a device has children before really_probe() is called
for it (which is not uncommon), that call will cause it to be
reordered after the children in the devices_kset list and the
ordering of that list will not reflect the correct device shutdown
order any more.

Also it causes the devices_kset list to be constantly reordered
until all drivers have been probed which is totally pointless
overhead in the majority of cases and it only covered an issue
with system shutdown, while system-wide suspend/resume potentially
had the same issue on the affected platforms (which was not covered).

Moreover, the shutdown issue originally addressed by the change in
really_probe() made by commit 52cdbdd4 is not present in 4.18-rc
any more, since dra7 started to use the sdhci-omap driver which
doesn't disable any regulators during shutdown, so the really_probe()
part of commit 52cdbdd4 can be safely reverted.  [The original
issue was related to the omap_hsmmc driver used by dra7 previously.]

For the above reasons, revert the really_probe() modifications made
by commit 52cdbdd4.

The other code changes made by commit 52cdbdd4 are useful and
they need not be reverted.

Fixes: 52cdbdd4 (driver core: correct device's shutdown order)
Link: https://lore.kernel.org/lkml/CAFgQCTt7VfqM=UyCnvNFxrSw8Z6cUtAi3HUwR4_xPAc03SgHjQ@mail.gmail.com/Reported-by: NPingfan Liu <kernelfans@gmail.com>
Tested-by: NPingfan Liu <kernelfans@gmail.com>
Reviewed-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      722e5f2b
    • R
      PM / Domains: Stop deferring probe at the end of initcall · e01afc32
      由 Rob Herring 提交于 
      All PM domain drivers must be built-in (at least those using DT), so
there is no point deferring probe after initcalls are done. Continuing
to defer probe may prevent booting successfully even if managing PM
domains is not required. This can happen if the user failed to enable
the driver or if power-domains are added to a platform's DT, but there
is not yet a driver (e.g. a new DTB with an old kernel).

Call the driver core function driver_deferred_probe_check_init_done()
instead of just returning -EPROBE_DEFER to stop deferring probe when
initcalls are done.
Acked-by: N"Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e01afc32
    • R
      driver core: allow stopping deferred probe after init · 25b4e70d
      由 Rob Herring 提交于 
      Deferred probe will currently wait forever on dependent devices to probe,
but sometimes a driver will never exist. It's also not always critical for
a driver to exist. Platforms can rely on default configuration from the
bootloader or reset defaults for things such as pinctrl and power domains.
This is often the case with initial platform support until various drivers
get enabled. There's at least 2 scenarios where deferred probe can render
a platform broken. Both involve using a DT which has more devices and
dependencies than the kernel supports. The 1st case is a driver may be
disabled in the kernel config. The 2nd case is the kernel version may
simply not have the dependent driver. This can happen if using a newer DT
(provided by firmware perhaps) with a stable kernel version. Deferred
probe issues can be difficult to debug especially if the console has
dependencies or userspace fails to boot to a shell.

There are also cases like IOMMUs where only built-in drivers are
supported, so deferring probe after initcalls is not needed. The IOMMU
subsystem implemented its own mechanism to handle this using OF_DECLARE
linker sections.

This commit adds makes ending deferred probe conditional on initcalls
being completed or a debug timeout. Subsystems or drivers may opt-in by
calling driver_deferred_probe_check_init_done() instead of
unconditionally returning -EPROBE_DEFER. They may use additional
information from DT or kernel's config to decide whether to continue to
defer probe or not.

The timeout mechanism is intended for debug purposes and WARNs loudly.
The remaining deferred probe pending list will also be dumped after the
timeout. Not that this timeout won't work for the console which needs
to be enabled before userspace starts. However, if the console's
dependencies are resolved, then the kernel log will be printed (as
opposed to no output).

Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      25b4e70d
  45. 09 7月, 2018 4 次提交
  47. 08 7月, 2018 1 次提交
    • J
      driver core: add a debugfs entry to show deferred devices · 28af109a
      由 Javier Martinez Canillas 提交于 
      With Device Trees (DT), the dependencies of the devices are defined in the
DT, then the drivers parse that information to lookup the needed resources
that have as dependencies.

Since drivers and devices are registered in a non-deterministic way, it is
possible that a device that is a dependency has not been registered yet by
the time that is looked up.

In this case the driver that requires this dependency cannot probe and has
to defer it. So the driver core adds it to a list of deferred devices that
is iterated again every time that a new driver is probed successfully.

For debugging purposes it may be useful to know what are the devices whose
probe function was deferred. Add a debugfs entry showing that information.

  $ cat /sys/kernel/debug/devices_deferred
  48070000.i2c:twl@48:bci
  musb-hdrc.0.auto
  omapdrm.0

This information could be obtained partially by enabling debugging, but it
means that the kernel log has to be parsed and the probe deferral balanced
with the successes. This can be error probe and has to be done in a ad-hoc
manner by everyone who needs to debug these kind of issues.

Since the information is already known by the kernel, just show it to make
it easier to debug.
Signed-off-by: NJavier Martinez Canillas <javierm@redhat.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      28af109a
  49. 07 7月, 2018 1 次提交