From: Andre Przywara andre.przywara@arm.com
[ Upstream commit 24201a64770afe2e17050b2ab9e8c0e24e9c23b2 ]
The DMA error handler routine is currently a tasklet, scheduled to run after the DMA error IRQ was handled. However it needs to take the MDIO mutex, which is not allowed to do in a tasklet. A kernel (with debug options) complains consequently: [ 614.050361] net eth0: DMA Tx error 0x174019 [ 614.064002] net eth0: Current BD is at: 0x8f84aa0ce [ 614.080195] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935 [ 614.109484] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 40, name: kworker/u4:4 [ 614.135428] 3 locks held by kworker/u4:4/40: [ 614.149075] #0: ffff000879863328 ((wq_completion)rpciod){....}, at: process_one_work+0x1f0/0x6a8 [ 614.177528] #1: ffff80001251bdf8 ((work_completion)(&task->u.tk_work)){....}, at: process_one_work+0x1f0/0x6a8 [ 614.209033] #2: ffff0008784e0110 (sk_lock-AF_INET-RPC){....}, at: tcp_sendmsg+0x24/0x58 [ 614.235429] CPU: 0 PID: 40 Comm: kworker/u4:4 Not tainted 5.6.0-rc3-00926-g4a165a9d5921 #26 [ 614.260854] Hardware name: ARM Test FPGA (DT) [ 614.274734] Workqueue: rpciod rpc_async_schedule [ 614.289022] Call trace: [ 614.296871] dump_backtrace+0x0/0x1a0 [ 614.308311] show_stack+0x14/0x20 [ 614.318751] dump_stack+0xbc/0x100 [ 614.329403] ___might_sleep+0xf0/0x140 [ 614.341018] __might_sleep+0x4c/0x80 [ 614.352201] __mutex_lock+0x5c/0x8a8 [ 614.363348] mutex_lock_nested+0x1c/0x28 [ 614.375654] axienet_dma_err_handler+0x38/0x388 [ 614.389999] tasklet_action_common.isra.15+0x160/0x1a8 [ 614.405894] tasklet_action+0x24/0x30 [ 614.417297] efi_header_end+0xe0/0x494 [ 614.429020] irq_exit+0xd0/0xd8 [ 614.439047] __handle_domain_irq+0x60/0xb0 [ 614.451877] gic_handle_irq+0xdc/0x2d0 [ 614.463486] el1_irq+0xcc/0x180 [ 614.473451] __tcp_transmit_skb+0x41c/0xb58 [ 614.486513] tcp_write_xmit+0x224/0x10a0 [ 614.498792] __tcp_push_pending_frames+0x38/0xc8 [ 614.513126] tcp_rcv_established+0x41c/0x820 [ 614.526301] tcp_v4_do_rcv+0x8c/0x218 [ 614.537784] __release_sock+0x5c/0x108 [ 614.549466] release_sock+0x34/0xa0 [ 614.560318] tcp_sendmsg+0x40/0x58 [ 614.571053] inet_sendmsg+0x40/0x68 [ 614.582061] sock_sendmsg+0x18/0x30 [ 614.593074] xs_sendpages+0x218/0x328 [ 614.604506] xs_tcp_send_request+0xa0/0x1b8 [ 614.617461] xprt_transmit+0xc8/0x4f0 [ 614.628943] call_transmit+0x8c/0xa0 [ 614.640028] __rpc_execute+0xbc/0x6f8 [ 614.651380] rpc_async_schedule+0x28/0x48 [ 614.663846] process_one_work+0x298/0x6a8 [ 614.676299] worker_thread+0x40/0x490 [ 614.687687] kthread+0x134/0x138 [ 614.697804] ret_from_fork+0x10/0x18 [ 614.717319] xilinx_axienet 7fe00000.ethernet eth0: Link is Down [ 615.748343] xilinx_axienet 7fe00000.ethernet eth0: Link is Up - 1Gbps/Full - flow control off
Since tasklets are not really popular anymore anyway, lets convert this over to a work queue, which can sleep and thus can take the MDIO mutex.
Signed-off-by: Andre Przywara andre.przywara@arm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/xilinx/xilinx_axienet.h | 2 +- .../net/ethernet/xilinx/xilinx_axienet_main.c | 24 +++++++++---------- 2 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet.h b/drivers/net/ethernet/xilinx/xilinx_axienet.h index 2dacfc85b3baa..04e51af32178c 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet.h +++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h @@ -435,7 +435,7 @@ struct axienet_local { void __iomem *regs; void __iomem *dma_regs;
- struct tasklet_struct dma_err_tasklet; + struct work_struct dma_err_task;
int tx_irq; int rx_irq; diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 479325eeaf8a0..345a795666e92 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -806,7 +806,7 @@ static irqreturn_t axienet_tx_irq(int irq, void *_ndev) /* Write to the Rx channel control register */ axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
- tasklet_schedule(&lp->dma_err_tasklet); + schedule_work(&lp->dma_err_task); axienet_dma_out32(lp, XAXIDMA_TX_SR_OFFSET, status); } out: @@ -855,7 +855,7 @@ static irqreturn_t axienet_rx_irq(int irq, void *_ndev) /* write to the Rx channel control register */ axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
- tasklet_schedule(&lp->dma_err_tasklet); + schedule_work(&lp->dma_err_task); axienet_dma_out32(lp, XAXIDMA_RX_SR_OFFSET, status); } out: @@ -891,7 +891,7 @@ static irqreturn_t axienet_eth_irq(int irq, void *_ndev) return IRQ_HANDLED; }
-static void axienet_dma_err_handler(unsigned long data); +static void axienet_dma_err_handler(struct work_struct *work);
/** * axienet_open - Driver open routine. @@ -935,9 +935,8 @@ static int axienet_open(struct net_device *ndev)
phylink_start(lp->phylink);
- /* Enable tasklets for Axi DMA error handling */ - tasklet_init(&lp->dma_err_tasklet, axienet_dma_err_handler, - (unsigned long) lp); + /* Enable worker thread for Axi DMA error handling */ + INIT_WORK(&lp->dma_err_task, axienet_dma_err_handler);
/* Enable interrupts for Axi DMA Tx */ ret = request_irq(lp->tx_irq, axienet_tx_irq, IRQF_SHARED, @@ -966,7 +965,7 @@ err_rx_irq: err_tx_irq: phylink_stop(lp->phylink); phylink_disconnect_phy(lp->phylink); - tasklet_kill(&lp->dma_err_tasklet); + cancel_work_sync(&lp->dma_err_task); dev_err(lp->dev, "request_irq() failed\n"); return ret; } @@ -1025,7 +1024,7 @@ static int axienet_stop(struct net_device *ndev) axienet_mdio_enable(lp); mutex_unlock(&lp->mii_bus->mdio_lock);
- tasklet_kill(&lp->dma_err_tasklet); + cancel_work_sync(&lp->dma_err_task);
if (lp->eth_irq > 0) free_irq(lp->eth_irq, ndev); @@ -1505,17 +1504,18 @@ static const struct phylink_mac_ops axienet_phylink_ops = { };
/** - * axienet_dma_err_handler - Tasklet handler for Axi DMA Error - * @data: Data passed + * axienet_dma_err_handler - Work queue task for Axi DMA Error + * @work: pointer to work_struct * * Resets the Axi DMA and Axi Ethernet devices, and reconfigures the * Tx/Rx BDs. */ -static void axienet_dma_err_handler(unsigned long data) +static void axienet_dma_err_handler(struct work_struct *work) { u32 axienet_status; u32 cr, i; - struct axienet_local *lp = (struct axienet_local *) data; + struct axienet_local *lp = container_of(work, struct axienet_local, + dma_err_task); struct net_device *ndev = lp->ndev; struct axidma_bd *cur_p;