Commit Graph

3 Commits

Author SHA1 Message Date
Sinan Kaya bdcfddfd74 dmaengine: qcom_hidma: make pending_tre_count atomic
Getting ready for the MSI interrupts. The pending_tre_count is used
in the interrupt handler to make sure all outstanding requests are
serviced.

The driver will allocate 11 MSI interrupts. Each MSI interrupt can be
assigned to a different CPU. Then, we have a race condition for common
variables as they share the same interrupt handler with a different
cause bit and they can potentially be executed in parallel. Making this
variable atomic so that it can be updated from multiple processor
contexts.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-11-03 18:55:44 +05:30
Sinan Kaya b5b809532e dmaengine: qcom_hidma: remove useless debugfs file removal
Since 'commit acc29fb8f7 ("debugfs: ->d_parent is never NULL or
negative")', HIDMA object removal is no longer working. This is due to
redundant debugfs remove call in hidma_debug_uninit.

debugfs_remove_recursive(dmadev->debugfs);
debugfs_remove_recursive(dmadev->stats);

The first remove is for the directory. Second remove is for the file under
the directory. The directory remove makes file remove invalid.

Unable to handle kernel NULL pointer dereference at virtual address

[<ffff00000889f480>] down_write+0x18/0x68
[<ffff00000831c220>] debugfs_remove_recursive+0x50/0x1c0
[<ffff00000848e0a8>] hidma_debug_uninit+0x20/0x30
[<ffff00000848c5d8>] hidma_remove+0x48/0x98
[<ffff000008511b6c>] platform_drv_remove+0x24/0x68
[<ffff00000850fac8>] __device_release_driver+0x80/0x118
[<ffff00000850fb84>] device_release_driver+0x24/0x38
[<ffff00000850e928>] unbind_store+0xe8/0x110
[<ffff00000850dd30>] drv_attr_store+0x20/0x30
[<ffff000008253a48>] sysfs_kf_write+0x48/0x58
[<ffff000008252dd8>] kernfs_fop_write+0xb0/0x1d8
[<ffff0000081dab3c>] __vfs_write+0x1c/0x110
[<ffff0000081db940>] vfs_write+0xa0/0x1b8
[<ffff0000081dcd34>] SyS_write+0x44/0xa0
[<ffff000008082ef0>] el0_svc_naked+0x24/0x28

Removing the second line.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-10-19 18:50:15 +05:30
Sinan Kaya 570d017629 dmaengine: qcom_hidma: add debugfs hooks
Add debugfs hooks for debugging the execution behavior of the DMA
channel. The debugfs hooks get initialized by the probe function and
uninitialized by the remove function.

A stats file is created in debugfs. The stats file will show the
information about each HIDMA channel as well as each asynchronous job
queued and completed at a given time.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-05-14 11:54:45 +05:30