From: Dmitry Osipenko <digetx@xxxxxxxxx> commit 94788af4ed039476ff3527b0e6a12c1dc42cb022 upstream. I was doing some experiments with I2C and noticed that Tegra APB DMA driver crashes sometime after I2C DMA transfer termination. The crash happens because tegra_dma_terminate_all() bails out immediately if pending list is empty, and thus, it doesn't release the half-completed descriptors which are getting re-used before ISR tasklet kicks-in. tegra-i2c 7000c400.i2c: DMA transfer timeout elants_i2c 0-0010: elants_i2c_irq: failed to read data: -110 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 142 at lib/list_debug.c:45 __list_del_entry_valid+0x45/0xac list_del corruption, ddbaac44->next is LIST_POISON1 (00000100) Modules linked in: CPU: 0 PID: 142 Comm: kworker/0:2 Not tainted 5.5.0-rc2-next-20191220-00175-gc3605715758d-dirty #538 Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) Workqueue: events_freezable_power_ thermal_zone_device_check [<c010e5c5>] (unwind_backtrace) from [<c010a1c5>] (show_stack+0x11/0x14) [<c010a1c5>] (show_stack) from [<c0973925>] (dump_stack+0x85/0x94) [<c0973925>] (dump_stack) from [<c011f529>] (__warn+0xc1/0xc4) [<c011f529>] (__warn) from [<c011f7e9>] (warn_slowpath_fmt+0x61/0x78) [<c011f7e9>] (warn_slowpath_fmt) from [<c042497d>] (__list_del_entry_valid+0x45/0xac) [<c042497d>] (__list_del_entry_valid) from [<c047a87f>] (tegra_dma_tasklet+0x5b/0x154) [<c047a87f>] (tegra_dma_tasklet) from [<c0124799>] (tasklet_action_common.constprop.0+0x41/0x7c) [<c0124799>] (tasklet_action_common.constprop.0) from [<c01022ab>] (__do_softirq+0xd3/0x2a8) [<c01022ab>] (__do_softirq) from [<c0124683>] (irq_exit+0x7b/0x98) [<c0124683>] (irq_exit) from [<c0168c19>] (__handle_domain_irq+0x45/0x80) [<c0168c19>] (__handle_domain_irq) from [<c043e429>] (gic_handle_irq+0x45/0x7c) [<c043e429>] (gic_handle_irq) from [<c0101aa5>] (__irq_svc+0x65/0x94) Exception stack(0xde2ebb90 to 0xde2ebbd8) Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> Acked-by: Jon Hunter <jonathanh@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200209163356.6439-2-digetx@xxxxxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/dma/tegra20-apb-dma.c | 4 ---- 1 file changed, 4 deletions(-) --- a/drivers/dma/tegra20-apb-dma.c +++ b/drivers/dma/tegra20-apb-dma.c @@ -755,10 +755,6 @@ static int tegra_dma_terminate_all(struc bool was_busy; spin_lock_irqsave(&tdc->lock, flags); - if (list_empty(&tdc->pending_sg_req)) { - spin_unlock_irqrestore(&tdc->lock, flags); - return 0; - } if (!tdc->busy) goto skip_dma_stop;
