kernel/linux.git/drivers/slimbus, branch v5.15.219

slimbus: qcom-ngd-ctrl: Register callbacks after creating the ngd

2026-07-24T13:51:16+00:00

[ Upstream commit 2a9d50e9ea406e0c8735938484adc20515ef1b47 ] When the remoteproc starts in parallel with the NGD driver being probed, or the remoteproc is already up when the PDR lookup is being registered, or in the theoretical event that we get an interrupt from the hardware, these callbacks will operate on uninitialized data. This result in issues to boot the affected boards. One such example can be seen in the following fault, where qcom_slim_ngd_ssr_pdr_notify() schedules work on the NULL ngd_up_work. [ 21.858578] ------------[ cut here ]------------ [ 21.858745] WARNING: kernel/workqueue.c:2338 at __queue_work+0x5e0/0x790, CPU#2: kworker/2:2/116 ... [ 21.859251] Call trace: [ 21.859255] __queue_work+0x5e0/0x790 (P) [ 21.859265] queue_work_on+0x6c/0xf0 [ 21.859273] qcom_slim_ngd_ssr_pdr_notify+0x110/0x150 [slim_qcom_ngd_ctrl] [ 21.859304] qcom_slim_ngd_ssr_notify+0x24/0x40 [slim_qcom_ngd_ctrl] [ 21.859318] notifier_call_chain+0xa4/0x230 [ 21.859329] srcu_notifier_call_chain+0x64/0xb8 [ 21.859338] ssr_notify_start+0x40/0x78 [qcom_common] [ 21.859355] rproc_start+0x130/0x230 [ 21.859367] rproc_boot+0x3d4/0x518 ... Move the enablement of interrupts, and the registration of SSR and PDR until after the NGD device has been registered. This could be further refined by moving initialization to the control driver probe and by removing the platform driver model from the picture. Fixes: 917809e2280b ("slimbus: ngd: Add qcom SLIMBus NGD driver") Cc: stable@vger.kernel.org Reviewed-by: Mukesh Ojha Signed-off-by: Bjorn Andersson Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260530204421.116824-6-srini@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

slimbus: Convert to platform remove callback returning void

2026-07-24T13:51:16+00:00

[ Upstream commit 880b33b0580c8ac9d0202b6e592cb116c99d1b65 ] 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() will be renamed to .remove(). Trivially convert the slimbus drivers from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20240430091657.35428-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 2a9d50e9ea40 ("slimbus: qcom-ngd-ctrl: Register callbacks after creating the ngd") Signed-off-by: Sasha Levin

slimbus: qcom-ngd-ctrl: Correct PDR and SSR cleanup ownership

2026-07-24T13:51:15+00:00

[ Upstream commit 960b53a3f76fa214c2fc493734ae7b3c5e713bbf ] PDR and SSR callbacks are registred from the controller probe function, but currently released from the child device's remove function. The remove() function should only be unwinding what was done in the same device's probe() function. Fixes: 917809e2280b ("slimbus: ngd: Add qcom SLIMBus NGD driver") Cc: stable@vger.kernel.org Reviewed-by: Dmitry Baryshkov Reviewed-by: Mukesh Ojha Signed-off-by: Bjorn Andersson Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260530204421.116824-5-srini@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

slimbus: qcom-ngd-ctrl: Fix probe error path ordering

2026-07-24T13:51:15+00:00

[ Upstream commit 2c22ff152d380ec3d3af099fa05d0ac5ca9b4c1e ] qcom_slim_ngd_ctrl_probe() first registers the SSR callback then allocates the PDR context, as such the error path needs to come in opposite order to allow us to unroll each step. Fixes: 16f14551d0df ("slimbus: qcom-ngd: cleanup in probe error path") Cc: stable@vger.kernel.org Reviewed-by: Dmitry Baryshkov Reviewed-by: Mukesh Ojha Signed-off-by: Bjorn Andersson Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260530204421.116824-4-srini@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

slimbus: qcom-ngd-ctrl: Fix up platform_driver registration

2026-07-24T13:51:15+00:00

[ Upstream commit 8663e8334d7b6007f5d8a4e5dd270246f35107a6 ] Device drivers should not invoke platform_driver_register()/unregister() in their probe and remove paths. They should further not rely on platform_driver_unregister() as their only means of "deleting" their child devices. Introduce a helper to unregister the child device and move the platform_driver_register()/unregister() to module_init()/exit(). Fixes: 917809e2280b ("slimbus: ngd: Add qcom SLIMBus NGD driver") Cc: stable@vger.kernel.org Reviewed-by: Dmitry Baryshkov Reviewed-by: Mukesh Ojha Signed-off-by: Bjorn Andersson Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260530204421.116824-3-srini@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

slimbus: qcom-ngd-ctrl: Avoid ABBA on tx_lock/ctrl->lock

2026-06-19T11:33:39+00:00

commit 55f2ea9ff83cc27a85526b14bc9b32f96a08d6ec upstream. During the SSR/PDR down notification the tx_lock is taken with the intent to provide synchronization with active DMA transfers. But during this period qcom_slim_ngd_down() is invoked, which ends up in slim_report_absent(), which takes the slim_controller lock. In multiple other codepaths these two locks are taken in the opposite order (i.e. slim_controller then tx_lock). The result is a lockdep splat, and a possible deadlock: rprocctl/449 is trying to acquire lock: ffff00009793e620 (&ctrl->lock){+.+.}-{4:4}, at: slim_report_absent (drivers/slimbus/core.c:322) slimbus but task is already holding lock: ffff00009793fb50 (&ctrl->tx_lock){+.+.}-{4:4}, at: qcom_slim_ngd_ssr_pdr_notify (drivers/slimbus/qcom-ngd-ctrl.c:1475) slim_qcom_ngd_ctrl which lock already depends on the new lock. Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ctrl->tx_lock); lock(&ctrl->lock); lock(&ctrl->tx_lock); lock(&ctrl->lock); The assumption is that the comment refers to the desire to not call qcom_slim_ngd_exit_dma() while we have an ongoing DMA TX transaction. But any such transaction is initiated and completed within a single qcom_slim_ngd_xfer_msg(). Prior to calling qcom_slim_ngd_exit_dma() the slim_controller is torn down, all child devices are notified that the slimbus is gone and the child devices are removed. Stop taking the tx_lock in qcom_slim_ngd_ssr_pdr_notify() to avoid the deadlock. Fixes: a899d324863a ("slimbus: qcom-ngd-ctrl: add Sub System Restart support") Cc: stable@vger.kernel.org Signed-off-by: Bjorn Andersson Signed-off-by: Srinivas Kandagatla Link: https://patch.msgid.link/20260530204421.116824-9-srini@kernel.org Signed-off-by: Greg Kroah-Hartman

slimbus: core: fix device reference leak on report present

2026-02-06T15:41:57+00:00

commit 9391380eb91ea5ac792aae9273535c8da5b9aa01 upstream. Slimbus devices can be allocated dynamically upon reception of report-present messages. Make sure to drop the reference taken when looking up already registered devices. Note that this requires taking an extra reference in case the device has not yet been registered and has to be allocated. Fixes: 46a2bb5a7f7e ("slimbus: core: Add slim controllers support") Cc: stable@vger.kernel.org # 4.16 Signed-off-by: Johan Hovold Link: https://patch.msgid.link/20251126145329.5022-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

slimbus: core: fix runtime PM imbalance on report present

2026-02-06T15:41:57+00:00

commit 0eb4ff6596114aabba1070a66afa2c2f5593739f upstream. Make sure to balance the runtime PM usage count in case slimbus device or address allocation fails on report present, which would otherwise prevent the controller from suspending. Fixes: 4b14e62ad3c9 ("slimbus: Add support for 'clock-pause' feature") Cc: stable@vger.kernel.org # 4.16 Signed-off-by: Johan Hovold Link: https://patch.msgid.link/20251126145329.5022-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman

slimbus: ngd: Fix reference count leak in qcom_slim_ngd_notify_slaves

2025-12-06T21:09:35+00:00

commit 96cf8500934e0ce2a6c486f1dbc3b1fff12f7a5e upstream. The function qcom_slim_ngd_notify_slaves() calls of_slim_get_device() which internally uses device_find_child() to obtain a device reference. According to the device_find_child() documentation, the caller must drop the reference with put_device() after use. Found via static analysis and this is similar to commit 4e65bda8273c ("ASoC: wcd934x: fix error handling in wcd934x_codec_parse_data()") Fixes: 917809e2280b ("slimbus: ngd: Add qcom SLIMBus NGD driver") Cc: stable Signed-off-by: Miaoqian Lin Reviewed-by: Dmitry Baryshkov Link: https://patch.msgid.link/20251027060601.33228-1-linmq006@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

slimbus: messaging: Free transaction ID in delayed interrupt scenario

2025-03-13T11:51:10+00:00

commit dcb0d43ba8eb9517e70b1a0e4b0ae0ab657a0e5a upstream. In case of interrupt delay for any reason, slim_do_transfer() returns timeout error but the transaction ID (TID) is not freed. This results into invalid memory access inside qcom_slim_ngd_rx_msgq_cb() due to invalid TID. Fix the issue by freeing the TID in slim_do_transfer() before returning timeout error to avoid invalid memory access. Call trace: __memcpy_fromio+0x20/0x190 qcom_slim_ngd_rx_msgq_cb+0x130/0x290 [slim_qcom_ngd_ctrl] vchan_complete+0x2a0/0x4a0 tasklet_action_common+0x274/0x700 tasklet_action+0x28/0x3c _stext+0x188/0x620 run_ksoftirqd+0x34/0x74 smpboot_thread_fn+0x1d8/0x464 kthread+0x178/0x238 ret_from_fork+0x10/0x20 Code: aa0003e8 91000429 f100044a 3940002b (3800150b) ---[ end trace 0fe00bec2b975c99 ]--- Kernel panic - not syncing: Oops: Fatal exception in interrupt. Fixes: afbdcc7c384b ("slimbus: Add messaging APIs to slimbus framework") Cc: stable Signed-off-by: Visweswara Tanuku Link: https://lore.kernel.org/r/20250124125740.16897-1-quic_vtanuku@quicinc.com Signed-off-by: Greg Kroah-Hartman