kernel/drivers/dma/qcom/gpi.c, branch linux-rolling-stable

dmaengine: qcom: gpi: Fix memory leak in gpi_peripheral_config()

2026-01-11T16:42:38Z

Fix a memory leak in gpi_peripheral_config() where the original memory pointed to by gchan->config could be lost if krealloc() fails. The issue occurs when: 1. gchan->config points to previously allocated memory 2. krealloc() fails and returns NULL 3. The function directly assigns NULL to gchan->config, losing the reference to the original memory 4. The original memory becomes unreachable and cannot be freed Fix this by using a temporary variable to hold the krealloc() result and only updating gchan->config when the allocation succeeds. Found via static analysis and code review. Fixes: 5d0c3533a19f ("dmaengine: qcom: Add GPI dma driver") Cc: stable@vger.kernel.org Signed-off-by: Miaoqian Lin Reviewed-by: Bjorn Andersson Link: https://patch.msgid.link/20251029123421.91973-1-linmq006@gmail.com Signed-off-by: Vinod Koul

dmaengine: qcom: gpi: Add GPI Block event interrupt support

2025-10-16T12:17:56Z

GSI hardware generates an interrupt for each transfer completion. For multiple messages within a single transfer, this results in N interrupts for N messages, leading to significant software interrupt latency. To mitigate this latency, utilize Block Event Interrupt (BEI) mechanism. Enabling BEI instructs the GSI hardware to prevent interrupt generation and BEI is disabled when an interrupt is necessary. Large I2C transfer can be divided into chunks of messages internally. Interrupts are not expected for the messages for which BEI bit set, only the last message triggers an interrupt, indicating the completion of N messages. This BEI mechanism enhances overall transfer efficiency. Signed-off-by: Jyothi Kumar Seerapu Reviewed-by: Dmitry Baryshkov Signed-off-by: Vinod Koul

dmaengine: qcom: gpi: Drop unused gpi_write_reg_field()

2025-06-26T22:29:44Z

Static function gpi_write_reg_field() is not used, W=1 build: gpi.c:573:20: error: unused function 'gpi_write_reg_field' [-Werror,-Wunused-function] Fixes: 5d0c3533a19f ("dmaengine: qcom: Add GPI dma driver") Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20250525-dma-fixes-v1-3-89d06dac9bcb@linaro.org Signed-off-by: Vinod Koul

dmaengine: qcom: gpi: Add GPI immediate DMA support for SPI protocol

2024-12-24T10:35:42Z

The DMA TRE(Transfer ring element) buffer contains the DMA buffer address. Accessing data from this address can cause significant delays in SPI transfers, which can be mitigated to some extent by utilizing immediate DMA support. QCOM GPI DMA hardware supports an immediate DMA feature for data up to 8 bytes, storing the data directly in the DMA TRE buffer instead of the DMA buffer address. This enhancement enables faster SPI data transfers. This optimization reduces the average transfer time from 25 us to 16 us for a single SPI transfer of 8 bytes length, with a clock frequency of 50 MHz. Signed-off-by: Jyothi Kumar Seerapu Reviewed-by: Neil Armstrong Tested-by: Neil Armstrong # on SM8550-QRD Reviewed-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20241209075033.16860-1-quic_jseerapu@quicinc.com Signed-off-by: Vinod Koul

dmaengine: Fix spelling mistakes

2024-09-02T08:26:01Z

Correct spelling mistakes in the DMA engine to improve readability and clarity without altering functionality. Signed-off-by: Amit Vadhavana Reviewed-by: Kees Cook Reviewed-by: Dave Jiang Reviewed-by: Fenghua Yu Link: https://lore.kernel.org/r/20240831172949.13189-1-av2082000@gmail.com Signed-off-by: Vinod Koul

dmaengine: qcom: gpi: clean up the IRQ disable/enable in gpi_reset_chan()

2024-06-11T18:25:34Z

The calls write_lock/unlock_irq() disables and re-enables the IRQs. Calling spin_lock_irqsave() and spin_lock_restore() when the IRQs are already disabled doesn't do anything and just makes the code confusing. Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/8be473eb-65e0-42b4-b574-e61c3a7f62d8@moroto.mountain Signed-off-by: Vinod Koul

dmaengine: qcom: gpi: remove unused struct 'reg_info'

2024-06-11T18:25:34Z

'reg_info' was never used since it's initial commit 5d0c3533a19f ("dmaengine: qcom: Add GPI dma driver") Remove it. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Bryan O'Donoghue Reviewed-by: Frank Li Link: https://lore.kernel.org/r/20240517234024.231477-1-linux@treblig.org Signed-off-by: Vinod Koul

dmaengine: qcom: gpi: Use devm_platform_get_and_ioremap_resource()

2023-07-12T16:54:00Z

Convert platform_get_resource(), devm_ioremap_resource() to a single call to devm_platform_get_and_ioremap_resource(), as this is exactly what this function does. Signed-off-by: Yangtao Li Link: https://lore.kernel.org/r/20230705081856.13734-1-frank.li@vivo.com Signed-off-by: Vinod Koul

dma: gpi: remove spurious unlock in gpi_ch_init

2023-04-12T17:12:27Z

gpi_ch_init() doesn't lock the ctrl_lock mutex, so there is no need to unlock it too. Instead the mutex is handled by the function gpi_alloc_chan_resources(), which properly locks and unlocks the mutex. ===================================== WARNING: bad unlock balance detected! 6.3.0-rc5-00253-g99792582ded1-dirty #15 Not tainted ------------------------------------- kworker/u16:0/9 is trying to release lock (&gpii->ctrl_lock) at: [] gpi_alloc_chan_resources+0x108/0x5bc but there are no more locks to release! other info that might help us debug this: 6 locks held by kworker/u16:0/9: #0: ffff575740010938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x220/0x594 #1: ffff80000809bdd0 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x220/0x594 #2: ffff575740f2a0f8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x38/0x188 #3: ffff57574b5570f8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x38/0x188 #4: ffffb99d06a2f180 (of_dma_lock){+.+.}-{3:3}, at: of_dma_request_slave_channel+0x138/0x280 #5: ffffb99d06a2ee20 (dma_list_mutex){+.+.}-{3:3}, at: dma_get_slave_channel+0x28/0x10c stack backtrace: CPU: 7 PID: 9 Comm: kworker/u16:0 Not tainted 6.3.0-rc5-00253-g99792582ded1-dirty #15 Hardware name: Google Pixel 3 (DT) Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace+0xa0/0xfc show_stack+0x18/0x24 dump_stack_lvl+0x60/0xac dump_stack+0x18/0x24 print_unlock_imbalance_bug+0x130/0x148 lock_release+0x270/0x300 __mutex_unlock_slowpath+0x48/0x2cc mutex_unlock+0x20/0x2c gpi_alloc_chan_resources+0x108/0x5bc dma_chan_get+0x84/0x188 dma_get_slave_channel+0x5c/0x10c gpi_of_dma_xlate+0x110/0x1a0 of_dma_request_slave_channel+0x174/0x280 dma_request_chan+0x3c/0x2d4 geni_i2c_probe+0x544/0x63c platform_probe+0x68/0xc4 really_probe+0x148/0x2ac __driver_probe_device+0x78/0xe0 driver_probe_device+0x3c/0x160 __device_attach_driver+0xb8/0x138 bus_for_each_drv+0x84/0xe0 __device_attach+0x9c/0x188 device_initial_probe+0x14/0x20 bus_probe_device+0xac/0xb0 device_add+0x60c/0x7d8 of_device_add+0x44/0x60 of_platform_device_create_pdata+0x90/0x124 of_platform_bus_create+0x15c/0x3c8 of_platform_populate+0x58/0xf8 devm_of_platform_populate+0x58/0xbc geni_se_probe+0xf0/0x164 platform_probe+0x68/0xc4 really_probe+0x148/0x2ac __driver_probe_device+0x78/0xe0 driver_probe_device+0x3c/0x160 __device_attach_driver+0xb8/0x138 bus_for_each_drv+0x84/0xe0 __device_attach+0x9c/0x188 device_initial_probe+0x14/0x20 bus_probe_device+0xac/0xb0 deferred_probe_work_func+0x8c/0xc8 process_one_work+0x2bc/0x594 worker_thread+0x228/0x438 kthread+0x108/0x10c ret_from_fork+0x10/0x20 Fixes: 5d0c3533a19f ("dmaengine: qcom: Add GPI dma driver") Signed-off-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20230409233355.453741-1-dmitry.baryshkov@linaro.org Signed-off-by: Vinod Koul

dmaengine: qcom: gpi: Set link_rx bit on GO TRE for rx operation

2022-12-28T06:56:11Z

Rx operation on SPI GSI DMA is currently not working. As per GSI spec, link_rx bit is to be set on GO TRE on tx channel whenever there is going to be a DMA TRE on rx channel. This is currently set for duplex operation only. Set the bit for rx operation as well. This is part of changes required to bring up Rx. Fixes: 94b8f0e58fa1 ("dmaengine: qcom: gpi: set chain and link flag for duplex") Signed-off-by: Vijaya Krishna Nivarthi Reviewed-by: Douglas Anderson Link: https://lore.kernel.org/r/1671212293-14767-1-git-send-email-quic_vnivarth@quicinc.com Signed-off-by: Vinod Koul