Andy Shevchenko 4831e0d905 serial: 8250_mid: handle interrupt correctly in DMA case ... Starting from Tangier B0 and continuing on Anniedale the HSU DMA interrupt line is actually shared with UART. Handling them independently is racy and quite often comes with the following traceback. irq 54: nobody cared (try booting with the "irqpoll" option) CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc6-edison64-86244934+ #1 Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48 ffff88003f203eb0 ffffffff8130e718 ffff880032627000 ffff88003262709c ffff88003f203ed8 ffffffff810a3960 ffff880032627000 0000000000000000 ffff880032627000 ffff88003f203f10 ffffffff810a3cc7 ffff880032627000 Call Trace: <IRQ> [<ffffffff8130e718>] dump_stack+0x4d/0x65 [<ffffffff810a3960>] __report_bad_irq+0x30/0xc0 [<ffffffff810a3cc7>] note_interrupt+0x227/0x270 [<ffffffff810a1380>] handle_irq_event_percpu+0x40/0x50 [<ffffffff810a13b7>] handle_irq_event+0x27/0x50 [<ffffffff810a42d5>] handle_fasteoi_irq+0x85/0x150 [<ffffffff8101d7fe>] handle_irq+0x6e/0x120 [<ffffffff8105b8bc>] ? _local_bh_enable+0x1c/0x50 [<ffffffff8101d0d6>] do_IRQ+0x46/0xd0 [<ffffffff818cef3f>] common_interrupt+0x7f/0x7f <EOI> [<ffffffff818cdead>] ? mwait_idle+0x7d/0x140 [<ffffffff81024c9a>] arch_cpu_idle+0xa/0x10 [<ffffffff818ce150>] default_idle_call+0x20/0x30 [<ffffffff810908fd>] cpu_startup_entry+0x16d/0x1d0 [<ffffffff818c882d>] rest_init+0x6d/0x70 [<ffffffff81f93e8f>] start_kernel+0x3e2/0x3ef [<ffffffff81f9343d>] x86_64_start_reservations+0x38/0x3a [<ffffffff81f93529>] x86_64_start_kernel+0xea/0xed handlers: [<ffffffff81411670>] serial8250_interrupt Disabling IRQ #54 Fix this by handling interrupt only in one place. The issue is discussed here: https://github.com/andy-shev/linux/issues/5 Moreover this also fixes another bug when Rx DMA returns wrong residue and we can't rely on it. Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2017-01-19 14:20:23 +01:00
..
Kconfig	dmaengine: hsu: make the UART driver in control of selecting this driver	2015-10-17 21:22:08 -07:00
Makefile	dmaengine: append hsu DMA driver	2015-03-07 03:23:02 +01:00
hsu.c	dmaengine: hsu: refactor hsu_dma_do_irq() to return int	2016-09-02 15:05:48 +02:00
hsu.h	dmaengine updates for 4.7	2016-05-19 11:47:18 -07:00
pci.c	serial: 8250_mid: handle interrupt correctly in DMA case	2017-01-19 14:20:23 +01:00