Messages in this thread | | | Subject | Re: [PATCH] pch_dma: Fix channel locking | From | "Koul, Vinod" <> | Date | Thu, 14 Jul 2011 03:42:37 +0530 |
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On Wed, 2011-06-22 at 17:05 +0200, Alexander Stein wrote: > Fix for the following INFO message > > ================================= > [ INFO: inconsistent lock state ] > 2.6.39+ #89 > --------------------------------- > inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. > rs232/822 [HC1[1]:SC0[0]:HE0:SE1] takes: > (&(&pd_chan->lock)->rlock){?.....}, at: [<c123b9a1>] pdc_desc_get+0x16/0xab > {HARDIRQ-ON-W} state was registered at: > [<c104fe28>] mark_irqflags+0xbd/0x11a > [<c1050386>] __lock_acquire+0x501/0x6bb > [<c1050945>] lock_acquire+0x63/0x7b > [<c131c51d>] _raw_spin_lock_bh+0x43/0x51 > [<c123bee4>] pd_alloc_chan_resources+0x92/0x11e > [<c123ad62>] dma_chan_get+0x9b/0x107 > [<c123b2d1>] __dma_request_channel+0x61/0xdc > [<c11ba24b>] pch_request_dma+0x61/0x19e > [<c11bb3b8>] pch_uart_startup+0x16a/0x1a2 > [<c11b8446>] uart_startup+0x87/0x147 > [<c11b9183>] uart_open+0x117/0x13e > [<c11a5c7d>] tty_open+0x23c/0x34c > [<c1097705>] chrdev_open+0x140/0x15f > [<c10930a6>] __dentry_open.clone.14+0x14a/0x22b > [<c1093dfb>] nameidata_to_filp+0x36/0x40 > [<c109f28b>] do_last+0x513/0x635 > [<c109f4af>] path_openat+0x9c/0x2aa > [<c109f6e4>] do_filp_open+0x27/0x69 > [<c1093f02>] do_sys_open+0xfd/0x184 > [<c1093fad>] sys_open+0x24/0x2a > [<c131d58c>] sysenter_do_call+0x12/0x32 > irq event stamp: 2522 > hardirqs last enabled at (2521): [<c131ca3b>] _raw_spin_unlock_irqrestore+0x36/0x52 > hardirqs last disabled at (2522): [<c131db27>] common_interrupt+0x27/0x34 > softirqs last enabled at (2354): [<c102fa11>] __do_softirq+0x10a/0x11a > softirqs last disabled at (2299): [<c10041a4>] do_softirq+0x57/0xa4 > > other info that might help us debug this: > 2 locks held by rs232/822: > #0: (&tty->atomic_write_lock){+.+.+.}, at: [<c11a4b7a>] tty_write_lock+0x14/0x3c > #1: (&port_lock_key){-.....}, at: [<c11bad72>] pch_uart_interrupt+0x17/0x1e9 > > stack backtrace: > Pid: 822, comm: rs232 Not tainted 2.6.39+ #89 > Call Trace: > [<c1319f90>] ? printk+0x19/0x1b > [<c104f893>] print_usage_bug+0x184/0x18f > [<c104e5b1>] ? print_irq_inversion_bug+0x10e/0x10e > [<c104f943>] mark_lock_irq+0xa5/0x1f6 > [<c104fc9c>] mark_lock+0x208/0x2d7 > [<c104fdc0>] mark_irqflags+0x55/0x11a > [<c1050386>] __lock_acquire+0x501/0x6bb > [<c10042ee>] ? dump_trace+0x92/0xb6 > [<c1050945>] lock_acquire+0x63/0x7b > [<c123b9a1>] ? pdc_desc_get+0x16/0xab > [<c131c2d0>] _raw_spin_lock+0x3e/0x4c > [<c123b9a1>] ? pdc_desc_get+0x16/0xab > [<c123b9a1>] pdc_desc_get+0x16/0xab > [<c10504d8>] ? __lock_acquire+0x653/0x6bb > [<c123bb2c>] pd_prep_slave_sg+0x7c/0x1cb > [<c1006c3f>] ? nommu_map_sg+0x6e/0x81 > [<c11bace6>] dma_handle_tx+0x2cf/0x344 > [<c11bad72>] ? pch_uart_interrupt+0x17/0x1e9 > [<c11baebb>] pch_uart_interrupt+0x160/0x1e9 > [<c10642fb>] handle_irq_event_percpu+0x25/0x127 > [<c1064429>] handle_irq_event+0x2c/0x43 > [<c1065e0d>] ? handle_fasteoi_irq+0x84/0x84 > [<c1065eb9>] handle_edge_irq+0xac/0xce > <IRQ> [<c1003ecb>] ? do_IRQ+0x38/0x9d > [<c131db2e>] ? common_interrupt+0x2e/0x34 > [<c105007b>] ? __lock_acquire+0x1f6/0x6bb > [<c131ca3d>] ? _raw_spin_unlock_irqrestore+0x38/0x52 > [<c11b798b>] ? uart_start+0x2d/0x32 > [<c11b7998>] ? uart_flush_chars+0x8/0xa > [<c11a7962>] ? n_tty_write+0x12c/0x1c6 > [<c1027a73>] ? try_to_wake_up+0x251/0x251 > [<c11a4d0b>] ? tty_write+0x169/0x1dc > [<c11a7836>] ? n_tty_ioctl+0xb7/0xb7 > [<c1094841>] ? vfs_write+0x91/0x10d > [<c11a4ba2>] ? tty_write_lock+0x3c/0x3c > [<c1094a69>] ? sys_write+0x3e/0x63 > [<c131d58c>] ? sysenter_do_call+0x12/0x32 > > Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> > --- > I'm not exactly sure if the dmaengine functions are allowed to be called from > IRQ context. But I found amba-pl011 which also calls device_prep_slave_sg from > IRQ context. > > drivers/dma/pch_dma.c | 16 ++++++++-------- > 1 files changed, 8 insertions(+), 8 deletions(-) > > diff --git a/drivers/dma/pch_dma.c b/drivers/dma/pch_dma.c > index ff5b38f..bfb0f19 100644 > --- a/drivers/dma/pch_dma.c > +++ b/drivers/dma/pch_dma.c > @@ -495,11 +495,11 @@ static int pd_alloc_chan_resources(struct dma_chan *chan) > list_add_tail(&desc->desc_node, &tmp_list); > } > > - spin_lock_bh(&pd_chan->lock); > + spin_lock_irq(&pd_chan->lock); > list_splice(&tmp_list, &pd_chan->free_list); > pd_chan->descs_allocated = i; > pd_chan->completed_cookie = chan->cookie = 1; > - spin_unlock_bh(&pd_chan->lock); > + spin_unlock_irq(&pd_chan->lock); > > pdc_enable_irq(chan, 1); > > @@ -517,10 +517,10 @@ static void pd_free_chan_resources(struct dma_chan *chan) > BUG_ON(!list_empty(&pd_chan->active_list)); > BUG_ON(!list_empty(&pd_chan->queue)); > > - spin_lock_bh(&pd_chan->lock); > + spin_lock_irq(&pd_chan->lock); > list_splice_init(&pd_chan->free_list, &tmp_list); > pd_chan->descs_allocated = 0; > - spin_unlock_bh(&pd_chan->lock); > + spin_unlock_irq(&pd_chan->lock); > > list_for_each_entry_safe(desc, _d, &tmp_list, desc_node) > pci_pool_free(pd->pool, desc, desc->txd.phys); > @@ -536,10 +536,10 @@ static enum dma_status pd_tx_status(struct dma_chan *chan, dma_cookie_t cookie, > dma_cookie_t last_completed; > int ret; > > - spin_lock_bh(&pd_chan->lock); > + spin_lock_irq(&pd_chan->lock); > last_completed = pd_chan->completed_cookie; > last_used = chan->cookie; > - spin_unlock_bh(&pd_chan->lock); > + spin_unlock_irq(&pd_chan->lock); > > ret = dma_async_is_complete(cookie, last_completed, last_used); > > @@ -654,7 +654,7 @@ static int pd_device_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, > if (cmd != DMA_TERMINATE_ALL) > return -ENXIO; > > - spin_lock_bh(&pd_chan->lock); > + spin_lock_irq(&pd_chan->lock); > > pdc_set_mode(&pd_chan->chan, DMA_CTL0_DISABLE); > > @@ -664,7 +664,7 @@ static int pd_device_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, > list_for_each_entry_safe(desc, _d, &list, desc_node) > pdc_chain_complete(pd_chan, desc); > > - spin_unlock_bh(&pd_chan->lock); > + spin_unlock_irq(&pd_chan->lock); > > return 0; > } Thanks applied with tested-by from Tomoya
-- ~Vinod
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