kernel.git/drivers/dma/at_xdmac.c, branch linux-6.3.y

dmaengine: at_xdmac: fix potential Oops in at_xdmac_prep_interleaved()

2023-06-09T08:47:47Z

[ Upstream commit 4d43acb145c363626d76f49febb4240c488cd1cf ] 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 Signed-off-by: Sasha Levin

dmaengine: at_xdmac: do not enable all cyclic channels

2023-05-11T14:17:36Z

[ Upstream commit f8435befd81dd85b7b610598551fadf675849bc1 ] 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 Signed-off-by: Sasha Levin

dmaengine: at_xdmac: restore the content of grws register

2023-05-11T14:17:35Z

[ Upstream commit 7c5eb63d16b01c202aaa95f374ae15a807745a73 ] 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 Signed-off-by: Sasha Levin

dmaengine: at_xdmac: do not resume channels paused by consumers

2023-05-11T14:17:35Z

[ Upstream commit 44fe8440bda545b5d167329df88c47609a645168 ] 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 Signed-off-by: Sasha Levin

dmaengine: at_xdmac: fix imbalanced runtime PM reference counter

2023-05-11T14:17:35Z

[ Upstream commit e53957e1ec5196671e49a48f90a5c9555153189a ] In case there are channels not paused during suspend (which on AT91 case is valid for serial driver when no_console_suspend boot argument is used) the at_xdmac_runtime_suspend_descriptors() was called more than one time due to at_xdmac_off(). To fix this add a new argument to at_xdmac_off() to specify if runtime PM reference counter needs to be decremented for queued active descriptors. Along with it moved the at_xdmac_runtime_suspend_descriptors() call under at_xdmac_chan_is_paused() check on suspend path as for the rest of channels the suspend is delayed by atmel_xdmac_prepare() in case channel is enabled. Same approach has been applied on resume path. Fixes: 650b0e990cbd ("dmaengine: at_xdmac: add runtime pm support") Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20230214151827.1050280-3-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: at_xdmac: disable/enable clock directly on suspend/resume

2023-05-11T14:17:35Z

[ Upstream commit 2de5ddb5e68c94b781b3789bca1ce52000d7d0e0 ] Runtime PM APIs for at_xdmac just plays with clk_enable()/clk_disable() letting aside the clk_prepare()/clk_unprepare() that needs to be executed as the clock is also prepared on probe. Thus instead of using runtime PM force suspend/resume APIs use clk_disable_unprepare() + pm_runtime_put_noidle() on suspend and clk_prepare_enable() + pm_runtime_get_noresume() on resume. This approach as been chosen instead of using runtime PM force suspend/resume with clk_unprepare()/clk_prepare() as it looks simpler and the final code is better. While at it added the missing pm_runtime_mark_last_busy() on suspend before decrementing the reference counter. Fixes: 650b0e990cbd ("dmaengine: at_xdmac: add runtime pm support") Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20230214151827.1050280-2-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: at_xdmac: remove empty line

2023-01-18T16:44:22Z

Remove empty line. Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20221117131547.293044-4-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: add runtime pm support

2023-01-18T16:44:22Z

Add runtime PM support which involves disabling/enabling controller's clocks on runtime PM suspend/resume ops. The runtime suspend/resume is done based on the work submitted to the controller: runtime resume is happening on at_xdmac_start_xfer() and runtime suspend on at_xdmac_tasklet(). Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20221117131547.293044-2-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: align properly function members

2023-01-18T16:44:22Z

Align properly function members. Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20221117131547.293044-3-claudiu.beznea@microchip.com Signed-off-by: Vinod Koul

dmaengine: at_xdmac: Replace two if statements with only one with two conditions

2022-09-05T06:31:55Z

Add a cosmetic change and replace two if statements with a single if statement with two conditions. In case the optional txstate parameter is NULL, we return the dma_cookie_status, which is fine, no functional change required. Signed-off-by: Tudor Ambarus Link: https://lore.kernel.org/r/20220802140630.243550-1-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul