From: Sergei Gavrikov <sergei.gavrikov@gmail.com>
To: thekyz@gmail.com
Cc: eCos Mailing List <ecos-discuss@ecos.sourceware.org>
Subject: Re: [ECOS] Can excessive/intensive serial flow cause stack overflow?
Date: Thu, 03 Jul 2008 19:11:00 -0000 [thread overview]
Message-ID: <486D2404.2010108@gmail.com> (raw)
In-Reply-To: <d5aafeec0807030906m1c97a6f1qcf09e8dd5b5f431f@mail.gmail.com>
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Alexandre wrote:
> On Thu, Jul 3, 2008 at 5:39 PM, Andrew Lunn <andrew@lunn.ch> wrote:
>> Duh... Didn't read the message correctly, so missed the obvious problem....
>>
>> I thought vector, then the problem is priority.....
>>
>> This is easy to explain. The actual serial driver is in
>> /packages/devs/serial/generic/16x5x/current/src.
>>
>> It registers the interrupt handler with:
>>
>> cyg_drv_interrupt_create(ser_chan->int_num,
>> CYG_IO_SERIAL_GENERIC_16X5X_INT_PRIORITY,
>> (cyg_addrword_t)chan,
>> pc_serial_ISR,
>> pc_serial_DSR,
>> &ser_chan->serial_interrupt_handle,
>> &ser_chan->serial_interrupt);
>>
>> The priority is hard coded for all serial devices as 4.
>>
>> You can sort of override this. The same file says:
>>
>> #ifndef CYG_IO_SERIAL_GENERIC_16X5X_INT_PRIORITY
>> # define CYG_IO_SERIAL_GENERIC_16X5X_INT_PRIORITY 4
>> #endif
>>
>> but you don't appear to be able to override it per device, just for
>> all devices. So i think you are not going to be able to benefit from
>> vectored interrupts and will have to use a priority of 16. Or you need
>> to have the serial driver to allow you to specify a priority level per
>> device.
>>
>> Humm, actually, you could do something a little horrible like:
>>
>> #define CYG_IO_SERIAL_GENERIC_16X5X_INT_PRIORITY \
>> (ser_chan->int_num == CYGNUM_HAL_INTERRUPT_UART0 ? 4 : 5)
>>
>> in arm_lpc2xxx_ser.inl
>>
>> Andrew
>
> That does the trick.
> The program stops there (after cyg_user_start(), some scheduler, clock
> and thread work) :
If I remember, in a past I did catch same asserts on LPC2XXX UARTS
ASSERT FAIL: (1) lpc2xxx_misc.c[472]hal_interrupt_set_level() Priority
already used by another vector
So, I just dirty tweaked the lpc2xxx_misc.c to shift priority to next
free slot. I found that my patch. Try to apply the patch and rebuild
eCos build tree. Today, I have no LPC2XXX hardware to test it.
Sergei
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diff -ur A/hal/arm/lpc2xxx/var/current/src/lpc2xxx_misc.c B/hal/arm/lpc2xxx/var/current/src/lpc2xxx_misc.c
--- A/hal/arm/lpc2xxx/var/current/src/lpc2xxx_misc.c
+++ B/hal/arm/lpc2xxx/var/current/src/lpc2xxx_misc.c
@@ -462,12 +462,18 @@
//
if (level < 16)
{
+ int i;
cyg_uint32 addr_offset = level << 2;
cyg_uint32 reg_val;
- HAL_READ_UINT32(CYGARC_HAL_LPC2XXX_REG_VIC_BASE +
- CYGARC_HAL_LPC2XXX_REG_VICVECTCNTL0 +
- addr_offset, reg_val);
+ for (i = level; i < 16; i++) {
+ addr_offset = i << 2;
+ HAL_READ_UINT32(CYGARC_HAL_LPC2XXX_REG_VIC_BASE +
+ CYGARC_HAL_LPC2XXX_REG_VICVECTCNTL0 +
+ addr_offset, reg_val);
+ if ((reg_val == 0) || (reg_val == (vector | 0x20)))
+ break;
+ }
CYG_ASSERT((reg_val == 0) || (reg_val == (vector | 0x20)),
"Priority already used by another vector");
HAL_WRITE_UINT32(CYGARC_HAL_LPC2XXX_REG_VIC_BASE +
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prev parent reply other threads:[~2008-07-03 19:11 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-03 9:58 Alexandre
2008-07-03 10:10 ` Andrew Lunn
2008-07-03 13:48 ` Alexandre
2008-07-03 14:05 ` Andrew Lunn
2008-07-03 14:52 ` Alexandre
2008-07-03 14:54 ` Alexandre
2008-07-03 14:59 ` Alexandre
2008-07-03 15:07 ` Alexandre
2008-07-03 15:24 ` Andrew Lunn
2008-07-03 15:30 ` Alexandre
2008-07-03 15:40 ` Andrew Lunn
2008-07-03 16:06 ` Alexandre
2008-07-03 19:11 ` Sergei Gavrikov [this message]
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