kernel/linux.git/drivers/dma/at_xdmac.c, branch v6.19.11

dmaengine: at_xdmac: Use pm_runtime_put_noidle() with many usage_counts

2025-04-17T15:08:10+00:00

We're holding more than one Runtime PM usage_counts in at_xdmac_device_terminate_all(). This makes pm_runtime_mark_last_busy() redundant and pm_runtime_put_autosuspend() misleading. Drop pm_runtime_mark_last_busy() and use pm_runtime_put_noidle() to decrement the usage_count, except in the case it may be the last. Signed-off-by: Sakari Ailus Link: https://lore.kernel.org/r/20250410065804.3676582-1-sakari.ailus@linux.intel.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: avoid null_prt_deref in at_xdmac_prep_dma_memset

2024-12-02T16:44:19+00:00

The at_xdmac_memset_create_desc may return NULL, which will lead to a null pointer dereference. For example, the len input is error, or the atchan->free_descs_list is empty and memory is exhausted. Therefore, add check to avoid this. Fixes: b206d9a23ac7 ("dmaengine: xdmac: Add memset support") Signed-off-by: Chen Ridong Link: https://lore.kernel.org/r/20241029082845.1185380-1-chenridong@huaweicloud.com Signed-off-by: Vinod Koul

dmaengine: Switch back to struct platform_driver::remove()

2024-10-14T18:20:34+00:00

After commit 0edb555a65d1 ("platform: Make platform_driver::remove() return void") .remove() is (again) the right callback to implement for platform drivers. Convert all platform drivers below drivers/dma after the previous conversion commits apart from the wireless drivers to use .remove(), with the eventual goal to drop struct platform_driver::remove_new(). As .remove() and .remove_new() have the same prototypes, conversion is done by just changing the structure member name in the driver initializer. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20241004062227.187726-2-u.kleine-koenig@baylibre.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Convert to platform remove callback returning void

2023-09-28T07:40:45+00:00

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Eventually after all drivers are converted, .remove_new() is renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20230919133207.1400430-5-u.kleine-koenig@pengutronix.de Signed-off-by: Vinod Koul

dmaengine: at_xdmac: fix potential Oops in at_xdmac_prep_interleaved()

2023-05-19T11:24:04+00:00

There are two place if the at_xdmac_interleaved_queue_desc() fails which could lead to a NULL dereference where "first" is NULL and we call list_add_tail(&first->desc_node, ...). In the first caller, the return is not checked so add a check for that. In the next caller, the return is checked but if it fails on the first iteration through the loop then it will lead to a NULL pointer dereference. Fixes: 4e5385784e69 ("dmaengine: at_xdmac: handle numf > 1") Fixes: 62b5cb757f1d ("dmaengine: at_xdmac: fix memory leak in interleaved mode") Signed-off-by: Dan Carpenter Reviewed-by: Tudor Ambarus Link: https://lore.kernel.org/r/21282b66-9860-410a-83df-39c17fcf2f1b@kili.mountain Signed-off-by: Vinod Koul

dmaengine: at_xdmac: align declaration of ret with the rest of variables

2023-04-12T17:48:44+00:00

Align the declaration of ret in atmel_xdmac_resume() with the rest of variables. Do this by adding ret to the line with declaration for i variable. Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20230214151827.1050280-8-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: add a warning message regarding for unpaused channels

2023-04-12T17:48:44+00:00

Add a warning message on suspend to let the user that there are channels not paused by their consumers. Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20230214151827.1050280-7-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: do not enable all cyclic channels

2023-04-12T17:48:44+00:00

Do not global enable all the cyclic channels in at_xdmac_resume(). Instead save the global status in at_xdmac_suspend() and re-enable the cyclic channel only if it was active before suspend. Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver") Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20230214151827.1050280-6-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: restore the content of grws register

2023-04-12T17:48:44+00:00

In case the system suspends to a deep sleep state where power to DMA controller is cut-off we need to restore the content of GRWS register. This is a write only register and writing bit X tells the controller to suspend read and write requests for channel X. Thus set GRWS before restoring the content of GE (Global Enable) regiter. Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver") Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20230214151827.1050280-5-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: do not resume channels paused by consumers

2023-04-12T17:48:44+00:00

In case there are DMA channels not paused by consumers in suspend process (valid on AT91 SoCs for serial driver when no_console_suspend) the driver pauses them (using at_xdmac_device_pause() which is also the same function called by dmaengine_pause()) and then in the resume process the driver resumes them calling at_xdmac_device_resume() which is the same function called by dmaengine_resume()). This is good for DMA channels not paused by consumers but for drivers that calls dmaengine_pause()/dmaegine_resume() on suspend/resume path this may lead to DMA channel being enabled before the IP is enabled. For IPs that needs strict ordering with regards to DMA channel enablement this will lead to wrong behavior. To fix this add a new set of functions at_xdmac_device_pause_internal()/at_xdmac_device_resume_internal() to be called only on suspend/resume. Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver") Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20230214151827.1050280-4-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul