linux-toradex.git/drivers/dma/at_hdmac.c, branch v5.11-rc6 Linux kernel for Apalis and Colibri modules dmaengine: at_hdmac: convert tasklets to use new tasklet_setup() API 2020-09-18T06:48:11+00:00 Allen Pais allen.lkml@gmail.com 2020-08-31T10:35:09+00:00 f6a0eb52743ce65ca6bbb1427f2a4032b53be65a In preparation for unconditionally passing the struct tasklet_struct pointer to all tasklet callbacks, switch to using the new tasklet_setup() and from_tasklet() to pass the tasklet pointer explicitly. Signed-off-by: Romain Perier <romain.perier@gmail.com> Signed-off-by: Allen Pais <allen.lkml@gmail.com> Link: https://lore.kernel.org/r/20200831103542.305571-3-allen.lkml@gmail.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
In preparation for unconditionally passing the
struct tasklet_struct pointer to all tasklet
callbacks, switch to using the new tasklet_setup()
and from_tasklet() to pass the tasklet pointer explicitly.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Link: https://lore.kernel.org/r/20200831103542.305571-3-allen.lkml@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: add missing kfree() call in at_dma_xlate() 2020-08-19T04:28:38+00:00 Yu Kuai yukuai3@huawei.com 2020-08-17T11:57:28+00:00 e097eb7473d9e70da9e03276f61cd392ccb9d79f If memory allocation for 'atslave' succeed, at_dma_xlate() doesn't have a corresponding kfree() in exception handling. Thus add kfree() for this function implementation. Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20200817115728.1706719-4-yukuai3@huawei.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
If memory allocation for 'atslave' succeed, at_dma_xlate() doesn't have a
corresponding kfree() in exception handling. Thus add kfree() for this
function implementation.

Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20200817115728.1706719-4-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: add missing put_device() call in at_dma_xlate() 2020-08-19T04:28:38+00:00 Yu Kuai yukuai3@huawei.com 2020-08-17T11:57:27+00:00 3832b78b3ec2cf51e07102f9b4480e343459b20f If of_find_device_by_node() succeed, at_dma_xlate() doesn't have a corresponding put_device(). Thus add put_device() to fix the exception handling for this function implementation. Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20200817115728.1706719-3-yukuai3@huawei.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
If of_find_device_by_node() succeed, at_dma_xlate() doesn't have a
corresponding put_device(). Thus add put_device() to fix the exception
handling for this function implementation.

Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20200817115728.1706719-3-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: check return value of of_find_device_by_node() in at_dma_xlate() 2020-08-19T04:28:37+00:00 Yu Kuai yukuai3@huawei.com 2020-08-17T11:57:26+00:00 0cef8e2c5a07d482ec907249dbd6687e8697677f The reurn value of of_find_device_by_node() is not checked, thus null pointer dereference will be triggered if of_find_device_by_node() failed. Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding") Signed-off-by: Yu Kuai <yukuai3@huawei.com> Link: https://lore.kernel.org/r/20200817115728.1706719-2-yukuai3@huawei.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
The reurn value of of_find_device_by_node() is not checked, thus null
pointer dereference will be triggered if of_find_device_by_node()
failed.

Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20200817115728.1706719-2-yukuai3@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: Repair parameter misspelling and demote non-kerneldoc headers 2020-07-15T12:20:46+00:00 Lee Jones lee.jones@linaro.org 2020-07-14T11:15:37+00:00 21e3cdb0234f7a687a624ab6d9eb92e19f60f743 Fixes the following W=1 kernel build warning(s): drivers/dma/at_hdmac.c:666: warning: Function parameter or member 'tx' not described in 'atc_tx_submit' drivers/dma/at_hdmac.c:666: warning: Excess function parameter 'desc' description in 'atc_tx_submit' drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'reg_width' not described in 'atc_dma_cyclic_check_values' drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'buf_addr' not described in 'atc_dma_cyclic_check_values' drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'period_len' not described in 'atc_dma_cyclic_check_values' drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'chan' not described in 'atc_dma_cyclic_fill_desc' drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'desc' not described in 'atc_dma_cyclic_fill_desc' drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'period_index' not described in 'atc_dma_cyclic_fill_desc' drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'buf_addr' not described in 'atc_dma_cyclic_fill_desc' drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'reg_width' not described in 'atc_dma_cyclic_fill_desc' drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'period_len' not described in 'atc_dma_cyclic_fill_desc' drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'direction' not described in 'atc_dma_cyclic_fill_desc' Signed-off-by: Lee Jones <lee.jones@linaro.org> Cc: Ludovic Desroches <ludovic.desroches@microchip.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Link: https://lore.kernel.org/r/20200714111546.1755231-9-lee.jones@linaro.org Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Fixes the following W=1 kernel build warning(s):

 drivers/dma/at_hdmac.c:666: warning: Function parameter or member 'tx' not described in 'atc_tx_submit'
 drivers/dma/at_hdmac.c:666: warning: Excess function parameter 'desc' description in 'atc_tx_submit'
 drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'reg_width' not described in 'atc_dma_cyclic_check_values'
 drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'buf_addr' not described in 'atc_dma_cyclic_check_values'
 drivers/dma/at_hdmac.c:1206: warning: Function parameter or member 'period_len' not described in 'atc_dma_cyclic_check_values'
 drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'chan' not described in 'atc_dma_cyclic_fill_desc'
 drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'desc' not described in 'atc_dma_cyclic_fill_desc'
 drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'period_index' not described in 'atc_dma_cyclic_fill_desc'
 drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'buf_addr' not described in 'atc_dma_cyclic_fill_desc'
 drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'reg_width' not described in 'atc_dma_cyclic_fill_desc'
 drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'period_len' not described in 'atc_dma_cyclic_fill_desc'
 drivers/dma/at_hdmac.c:1228: warning: Function parameter or member 'direction' not described in 'atc_dma_cyclic_fill_desc'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Link: https://lore.kernel.org/r/20200714111546.1755231-9-lee.jones@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: Fix deadlocks 2020-02-25T05:57:27+00:00 Tudor Ambarus tudor.ambarus@microchip.com 2020-01-23T14:03:11+00:00 078a6506141a4ce76bee6c257e9b14f5c606ee4c Fix the following deadlocks: 1/ atc_handle_cyclic() and atc_chain_complete() called dmaengine_desc_get_callback_invoke() while wrongly holding the atchan->lock. Clients can set the callback to dmaengine_terminate_sync() which will end up trying to get the same lock, thus a deadlock occurred. 2/ dma_run_dependencies() was called with the atchan->lock held, but the method calls device_issue_pending() which tries to get the same lock, and so a deadlock occurred. The driver must not hold the lock when invoking the callback or when running dependencies. Releasing the spinlock within a called function before calling the callback is not a nice thing to do -> called functions become non-atomic when called within an atomic region. Thus the lock is now taken in the child routines whereever is needed. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Link: https://lore.kernel.org/r/20200123140237.125799-6-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Fix the following deadlocks:
1/ atc_handle_cyclic() and atc_chain_complete() called
dmaengine_desc_get_callback_invoke() while wrongly holding the
atchan->lock. Clients can set the callback to dmaengine_terminate_sync()
which will end up trying to get the same lock, thus a deadlock occurred.
2/ dma_run_dependencies() was called with the atchan->lock held, but the
method calls device_issue_pending() which tries to get the same lock,
and so a deadlock occurred.

The driver must not hold the lock when invoking the callback or when
running dependencies. Releasing the spinlock within a called function
before calling the callback is not a nice thing to do -> called functions
become non-atomic when called within an atomic region. Thus the lock is
now taken in the child routines whereever is needed.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-6-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: Switch atomic allocations to GFP_NOWAIT 2020-02-25T05:57:27+00:00 Tudor Ambarus tudor.ambarus@microchip.com 2020-01-23T14:03:09+00:00 247b4d83d6525d04278333cf201d6e3b066c9ca5 Avoids sleeping without depleting the emergency pool. The rationale being that in most cases a dma device is either offloading an operation that will automatically fallback to software when the descriptor allocation fails, or we can simply poll and wait for the dma device to release some in use descriptors. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Link: https://lore.kernel.org/r/20200123140237.125799-5-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Avoids sleeping without depleting the emergency pool.
The rationale being that in most cases a dma device is either
offloading an operation that will automatically fallback to
software when the descriptor allocation fails, or we can simply poll
and wait for the dma device to release some in use descriptors.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-5-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: Drop description for a not defined parameter 2020-02-25T05:57:27+00:00 Tudor Ambarus tudor.ambarus@microchip.com 2020-01-23T14:03:07+00:00 ceb2c14c5908565ac49f9b6a5c0d9e93f2099ea0 Probably a leftover, drop it. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Link: https://lore.kernel.org/r/20200123140237.125799-4-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Probably a leftover, drop it.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-4-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: Return err in case the chan is not free at alloc res time 2020-02-25T05:57:27+00:00 Tudor Ambarus tudor.ambarus@microchip.com 2020-01-23T14:03:06+00:00 ad16bc232dd72f85984c790e07c69009b7c850c8 Having a list of descriptors allocated for the channel at device_alloc_chan_resources() time is a sign for bad free usage. Return err and add a debug message in case the channel is not free from a previous use. atchan->descs_allocated becomes useless, get rid of it. More, drop the error message in atc_desc_get() because now it would introduce an extra if statement. The callers of atc_desc_get() already print error messages in case the callee fails, no one is hurt. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Link: https://lore.kernel.org/r/20200123140237.125799-3-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
Having a list of descriptors allocated for the channel at
device_alloc_chan_resources() time is a sign for bad free usage.
Return err and add a debug message in case the channel is not
free from a previous use.

atchan->descs_allocated becomes useless, get rid of it. More,
drop the error message in atc_desc_get() because now it would
introduce an extra if statement. The callers of atc_desc_get()
already print error messages in case the callee fails, no one
is hurt.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-3-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
dmaengine: at_hdmac: Drop locking in at_hdmac_alloc_chan_resources() 2020-02-25T05:57:27+00:00 Tudor Ambarus tudor.ambarus@microchip.com 2020-01-23T14:03:04+00:00 bbc58394d81110f76586d3053fd5a3a3ad616050 There is no need for locking in device_alloc_chan_resources(), the DMA core takes care of it by using a dma_list_mutex around the DMA devices. Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Link: https://lore.kernel.org/r/20200123140237.125799-2-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul <vkoul@kernel.org> 
There is no need for locking in device_alloc_chan_resources(),
the DMA core takes care of it by using a dma_list_mutex around
the DMA devices.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20200123140237.125799-2-tudor.ambarus@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>