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>
There is new API in place which provides allocation mechanism of interrupts for
PCI devices. Use it in the HSU DMA driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Since we have nice macro IRQ_RETVAL() we would use it to convert a flag of
handled interrupt from int to irqreturn_t.
The rationale of doing this is:
a) hence we implicitly mark hsu_dma_do_irq() as an auxiliary function that
can't be used as interrupt handler directly, and
b) to be in align with serial driver which is using serial8250_handle_irq()
that returns plain int by design.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To allow other code to safely read DMA Channel Status Register (where
the register attribute for Channel Error, Descriptor Time Out &
Descriptor Done fields are read-clear), export hsu_dma_get_status().
hsu_dma_irq() is renamed to hsu_dma_do_irq() and requires Status
Register value to be passed in.
Signed-off-by: Chuah, Kim Tatt <kim.tatt.chuah@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are no platforms where it's not possible to calculate
the number of channels based on IO space length, and since
that is the only purpose for struct hsu_dma_platform_data,
removing it.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Intel Tangier is known to have the HSU DMA IP as PCI device 00:05.0. The patch
adds the ID as found on Intel Edison board to the PCI device table.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The HSU DMA is developed to support High Speed UART controllers found in
particular on Intel MID platforms such as Intel Medfield.
The existing implementation is tighten to the drivers/tty/serial/mfd.c driver
and has a lot of disadvantages. Besides that we would like to get rid of the
old HS UART driver in regarding to extending the 8250 which supports generic
DMAEngine API. That's why the current driver has been developed.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
