From c0cfb5767277856a41ae2dd1ed31dfd8cb37f2a0 Mon Sep 17 00:00:00 2001 From: Andy Voltz Date: Thu, 14 Mar 2013 15:09:50 -0400 Subject: Fix serial bug when recieving a file When serial-transmit a file from host to target, an error "BUG: scheduling while atomic: cat/998/0x00010002" occurs. BUG: scheduling while atomic: cat/998/0x00010002 Modules linked in: Pid: 998, comm: cat CPU: 0 Not tainted (3.0.15 #1) PC is at n_tty_write+0x260/0x43c LR is at tty_write_room+0x20/0x2c pc : <80204700> lr : <80206194> psr: 60000013 sp : 863b9e78 ip : 8038e378 fp : 863b9ec4 r10: 00000fff r9 : 863b6400 r8 : 86165d80 r7 : 863b8000 r6 : 86368b6c r5 : 86368800 r4 : 00000002 r3 : 00000010 r2 : 00000000 r1 : 00000040 r0 : 00000002 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 10c53c7d Table: 863f8059 DAC: 00000015 <80031f5c> (show_regs+0x0/0x54) from <803761f0> (__schedule_bug+0x4c/0x60) r4:863b9e30 r3:60000193 <803761a4> (__schedule_bug+0x0/0x60) from <8037941c> (__schedule+0x35c/0x3c4) Thanks to Tadayoshi Arai for reporting this and submitting this patch --- drivers/tty/serial/mvf.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/mvf.c b/drivers/tty/serial/mvf.c index a65a275c7c98..66dba76081e8 100644 --- a/drivers/tty/serial/mvf.c +++ b/drivers/tty/serial/mvf.c @@ -98,7 +98,7 @@ struct imx_port { void *rx_buf; unsigned char *tx_buf; unsigned int rx_bytes, tx_bytes; - struct work_struct tsk_dma_rx, tsk_dma_tx; + struct work_struct tsk_rx, tsk_dma_tx; unsigned int dma_tx_nents; bool dma_is_rxing, dma_is_txing; wait_queue_head_t dma_wait; @@ -384,6 +384,17 @@ out: return IRQ_HANDLED; } +static void rx_work(struct work_struct *w) +{ + struct imx_port *sport = container_of(w, struct imx_port, tsk_rx); + struct tty_struct *tty = sport->port.state->port.tty; + + if (sport->rx_bytes) { + tty_flip_buffer_push(tty); + sport->rx_bytes = 0; + } +} + static irqreturn_t imx_rxint(int irq, void *dev_id) { struct imx_port *sport = dev_id; @@ -445,12 +456,13 @@ static irqreturn_t imx_rxint(int irq, void *dev_id) uart_insert_char(sport->port, sr, MXC_UARTSR1_OR, rx, flg); */ tty_insert_flip_char(tty, rx, flg); + sport->rx_bytes++; } out: spin_unlock_irqrestore(&sport->port.lock, flags); - tty_flip_buffer_push(tty); + schedule_work(&sport->tsk_rx); return IRQ_HANDLED; } @@ -640,7 +652,7 @@ static int imx_startup(struct uart_port *port) sport->port.flags |= UPF_LOW_LATENCY; INIT_WORK(&sport->tsk_dma_tx, dma_tx_work); - /*INIT_WORK(&sport->tsk_dma_rx, dma_rx_work);*/ + INIT_WORK(&sport->tsk_rx, rx_work); init_waitqueue_head(&sport->dma_wait); } -- cgit v1.2.3