From: Quanyang Wang quanyang.wang@windriver.com
[ Upstream commit 538ea65a9fd1194352a41313bff876b74b5d90c5 ]
In some scenarios (kdump), dpdma hardware irqs has been enabled when calling request_irq in probe function, and then the dpdma irq handler xilinx_dpdma_irq_handler is invoked to access xdev->chan[i]. But at this moment xdev->chan[i] hasn't been initialized.
We should ensure the dpdma controller to be in a consistent and clean state before further initialization. So add dpdma_hw_init() to do this.
Furthermore, in xilinx_dpdma_disable_irq, disable all interrupts instead of error interrupts.
This patch is to fix the kdump kernel crash as below:
[ 3.696128] Unable to handle kernel NULL pointer dereference at virtual address 000000000000012c [ 3.696710] xilinx-zynqmp-dpdma fd4c0000.dma-controller: Xilinx DPDMA engine is probed [ 3.704900] Mem abort info: [ 3.704902] ESR = 0x96000005 [ 3.704905] EC = 0x25: DABT (current EL), IL = 32 bits [ 3.704907] SET = 0, FnV = 0 [ 3.704912] EA = 0, S1PTW = 0 [ 3.713800] ahci-ceva fd0c0000.ahci: supply ahci not found, using dummy regulator [ 3.715585] Data abort info: [ 3.715587] ISV = 0, ISS = 0x00000005 [ 3.715589] CM = 0, WnR = 0 [ 3.715592] [000000000000012c] user address but active_mm is swapper [ 3.715596] Internal error: Oops: 96000005 [#1] SMP [ 3.715599] Modules linked in: [ 3.715608] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.0-12170-g60894882155f-dirty #77 [ 3.723937] Hardware name: ZynqMP ZCU102 Rev1.0 (DT) [ 3.723942] pstate: 80000085 (Nzcv daIf -PAN -UAO -TCO BTYPE=--) [ 3.723956] pc : xilinx_dpdma_irq_handler+0x418/0x560 [ 3.793049] lr : xilinx_dpdma_irq_handler+0x3d8/0x560 [ 3.798089] sp : ffffffc01186bdf0 [ 3.801388] x29: ffffffc01186bdf0 x28: ffffffc011836f28 [ 3.806692] x27: ffffff8023e0ac80 x26: 0000000000000080 [ 3.811996] x25: 0000000008000408 x24: 0000000000000003 [ 3.817300] x23: ffffffc01186be70 x22: ffffffc011291740 [ 3.822604] x21: 0000000000000000 x20: 0000000008000408 [ 3.827908] x19: 0000000000000000 x18: 0000000000000010 [ 3.833212] x17: 0000000000000000 x16: 0000000000000000 [ 3.838516] x15: 0000000000000000 x14: ffffffc011291740 [ 3.843820] x13: ffffffc02eb4d000 x12: 0000000034d4d91d [ 3.849124] x11: 0000000000000040 x10: ffffffc0112d2d48 [ 3.854428] x9 : ffffffc0112d2d40 x8 : ffffff8021c00268 [ 3.859732] x7 : 0000000000000000 x6 : ffffffc011836000 [ 3.865036] x5 : 0000000000000003 x4 : 0000000000000000 [ 3.870340] x3 : 0000000000000001 x2 : 0000000000000000 [ 3.875644] x1 : 0000000000000000 x0 : 000000000000012c [ 3.880948] Call trace: [ 3.883382] xilinx_dpdma_irq_handler+0x418/0x560 [ 3.888079] __handle_irq_event_percpu+0x5c/0x178 [ 3.892774] handle_irq_event_percpu+0x34/0x98 [ 3.897210] handle_irq_event+0x44/0xb8 [ 3.901030] handle_fasteoi_irq+0xd0/0x190 [ 3.905117] generic_handle_irq+0x30/0x48 [ 3.909111] __handle_domain_irq+0x64/0xc0 [ 3.913192] gic_handle_irq+0x78/0xa0 [ 3.916846] el1_irq+0xc4/0x180 [ 3.919982] cpuidle_enter_state+0x134/0x2f8 [ 3.924243] cpuidle_enter+0x38/0x50 [ 3.927810] call_cpuidle+0x1c/0x40 [ 3.931290] do_idle+0x20c/0x270 [ 3.934502] cpu_startup_entry+0x28/0x58 [ 3.938410] rest_init+0xbc/0xcc [ 3.941631] arch_call_rest_init+0x10/0x1c [ 3.945718] start_kernel+0x51c/0x558
Fixes: 7cbb0c63de3f ("dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver") Signed-off-by: Quanyang Wang quanyang.wang@windriver.com Link: https://lore.kernel.org/r/20210430064041.4058180-1-quanyang.wang@windriver.c... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/xilinx/xilinx_dpdma.c | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c index 70b29bd079c9..ff7dfb3fdeb4 100644 --- a/drivers/dma/xilinx/xilinx_dpdma.c +++ b/drivers/dma/xilinx/xilinx_dpdma.c @@ -1459,7 +1459,7 @@ static void xilinx_dpdma_enable_irq(struct xilinx_dpdma_device *xdev) */ static void xilinx_dpdma_disable_irq(struct xilinx_dpdma_device *xdev) { - dpdma_write(xdev->reg, XILINX_DPDMA_IDS, XILINX_DPDMA_INTR_ERR_ALL); + dpdma_write(xdev->reg, XILINX_DPDMA_IDS, XILINX_DPDMA_INTR_ALL); dpdma_write(xdev->reg, XILINX_DPDMA_EIDS, XILINX_DPDMA_EINTR_ALL); }
@@ -1596,6 +1596,26 @@ static struct dma_chan *of_dma_xilinx_xlate(struct of_phandle_args *dma_spec, return dma_get_slave_channel(&xdev->chan[chan_id]->vchan.chan); }
+static void dpdma_hw_init(struct xilinx_dpdma_device *xdev) +{ + unsigned int i; + void __iomem *reg; + + /* Disable all interrupts */ + xilinx_dpdma_disable_irq(xdev); + + /* Stop all channels */ + for (i = 0; i < ARRAY_SIZE(xdev->chan); i++) { + reg = xdev->reg + XILINX_DPDMA_CH_BASE + + XILINX_DPDMA_CH_OFFSET * i; + dpdma_clr(reg, XILINX_DPDMA_CH_CNTL, XILINX_DPDMA_CH_CNTL_ENABLE); + } + + /* Clear the interrupt status registers */ + dpdma_write(xdev->reg, XILINX_DPDMA_ISR, XILINX_DPDMA_INTR_ALL); + dpdma_write(xdev->reg, XILINX_DPDMA_EISR, XILINX_DPDMA_EINTR_ALL); +} + static int xilinx_dpdma_probe(struct platform_device *pdev) { struct xilinx_dpdma_device *xdev; @@ -1622,6 +1642,8 @@ static int xilinx_dpdma_probe(struct platform_device *pdev) if (IS_ERR(xdev->reg)) return PTR_ERR(xdev->reg);
+ dpdma_hw_init(xdev); + xdev->irq = platform_get_irq(pdev, 0); if (xdev->irq < 0) { dev_err(xdev->dev, "failed to get platform irq\n");