kernel.git/drivers/dma/at_hdmac.c, branch linux-4.9.y

dmaengine: at_hdmac: Check return code of dma_async_device_register

2022-11-25T16:35:38Z

commit c47e6403fa099f200868d6b106701cb42d181d2b upstream. dma_async_device_register() can fail, check the return code and display an error. Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller") Signed-off-by: Tudor Ambarus Cc: stable@vger.kernel.org Acked-by: Nicolas Ferre Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com Link: https://lore.kernel.org/r/20221025090306.297886-16-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: Fix impossible condition

2022-11-25T16:35:38Z

commit 28cbe5a0a46a6637adbda52337d7b2777fc04027 upstream. The iterator can not be greater than ATC_MAX_DSCR_TRIALS, as the for loop will stop when i == ATC_MAX_DSCR_TRIALS. While here, use the common "i" name for the iterator. Fixes: 93dce3a6434f ("dmaengine: at_hdmac: fix residue computation") Signed-off-by: Tudor Ambarus Cc: stable@vger.kernel.org Acked-by: Nicolas Ferre Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com Link: https://lore.kernel.org/r/20221025090306.297886-15-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: Don't allow CPU to reorder channel enable

2022-11-25T16:35:38Z

commit 580ee84405c27d6ed419abe4d2b3de1968abdafd upstream. at_hdmac uses __raw_writel for register writes. In the absence of a barrier, the CPU may reorder the register operations. Introduce a write memory barrier so that the CPU does not reorder the channel enable, thus the start of the transfer, without making sure that all the pre-required register fields are already written. Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller") Reported-by: Peter Rosin Signed-off-by: Tudor Ambarus Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/ Acked-by: Nicolas Ferre Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com Link: https://lore.kernel.org/r/20221025090306.297886-14-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: Fix completion of unissued descriptor in case of errors

2022-11-25T16:35:37Z

commit ef2cb4f0ce479f77607b04c4b0414bf32f863ee8 upstream. In case the controller detected an error, the code took the chance to move all the queued (submitted) descriptors to the active (issued) list. This was wrong as if there were any descriptors in the submitted list they were moved to the issued list without actually issuing them to the controller, thus a completion could be raised without even fireing the descriptor. Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller") Reported-by: Peter Rosin Signed-off-by: Tudor Ambarus Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/ Acked-by: Nicolas Ferre Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com Link: https://lore.kernel.org/r/20221025090306.297886-13-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: Don't start transactions at tx_submit level

2022-11-25T16:35:37Z

commit 7176a6a8982d311e50a7c1168868d26e65bbba19 upstream. tx_submit is supposed to push the current transaction descriptor to a pending queue, waiting for issue_pending() to be called. issue_pending() must start the transfer, not tx_submit(), thus remove atc_dostart() from atc_tx_submit(). Clients of at_xdmac that assume that tx_submit() starts the transfer must be updated and call dma_async_issue_pending() if they miss to call it. The vdbg print was moved to after the lock is released. It is desirable to do the prints without the lock held if possible, and because the if statement disappears there's no reason why to do the print while holding the lock. Fixes: dc78baa2b90b ("dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller") Reported-by: Peter Rosin Signed-off-by: Tudor Ambarus Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/13c6c9a2-6db5-c3bf-349b-4c127ad3496a@axentia.se/ Acked-by: Nicolas Ferre Link: https://lore.kernel.org/r/20221025090306.297886-1-tudor.ambarus@microchip.com Link: https://lore.kernel.org/r/20221025090306.297886-3-tudor.ambarus@microchip.com Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: check return value of of_find_device_by_node() in at_dma_xlate()

2020-09-12T09:47:33Z

[ Upstream commit 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 Link: https://lore.kernel.org/r/20200817115728.1706719-2-yukuai3@huawei.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin

dmaengine: at_hdmac: fix module unloading

2018-12-05T18:42:40Z

commit 77e75fda94d2ebb86aa9d35fb1860f6395bf95de upstream. of_dma_controller_free() was not called on module onloading. This lead to a soft lockup: watchdog: BUG: soft lockup - CPU#0 stuck for 23s! Modules linked in: at_hdmac [last unloaded: at_hdmac] when of_dma_request_slave_channel() tried to call ofdma->of_dma_xlate(). Cc: stable@vger.kernel.org Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding") Acked-by: Ludovic Desroches Signed-off-by: Richard Genoud Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: fix memory leak in at_dma_xlate()

2018-12-05T18:42:40Z

commit 98f5f932254b88ce828bc8e4d1642d14e5854caa upstream. The leak was found when opening/closing a serial port a great number of time, increasing kmalloc-32 in slabinfo. Each time the port was opened, dma_request_slave_channel() was called. Then, in at_dma_xlate(), atslave was allocated with devm_kzalloc() and never freed. (Well, it was free at module unload, but that's not what we want). So, here, kzalloc is more suited for the job since it has to be freed in atc_free_chan_resources(). Cc: stable@vger.kernel.org Fixes: bbe89c8e3d59 ("at_hdmac: move to generic DMA binding") Reported-by: Mario Forner Suggested-by: Alexandre Belloni Acked-by: Alexandre Belloni Acked-by: Ludovic Desroches Signed-off-by: Richard Genoud Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved

2018-02-25T10:05:48Z

[ Upstream commit 62a277d43d47e74972de44d33bd3763e31992414 ] _xt_ is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after _xt_ has been null checked. This issue was detected with the help of Coccinelle. Fixes: 4483320e241c ("dmaengine: Use Pointer xt after NULL check.") Signed-off-by: Gustavo A. R. Silva Acked-by: Ludovic Desroches Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

dmaengine: at_hdmac: convert callback to helper function

2016-08-08T02:41:38Z

This is in preperation of moving to a callback that provides results to the callback for the transaction. The conversion will maintain current behavior and the driver must convert to new callback mechanism at a later time in order to receive results. Signed-off-by: Dave Jiang Reviewed-by: Lars-Peter Clausen Cc: Nicolas Ferre Signed-off-by: Vinod Koul