Changeset 78c84df in rtems


Ignore:
Timestamp:
Jun 10, 2010, 1:10:00 PM (9 years ago)
Author:
Gerardo Puga <glpuga@…>
Branches:
4.11, master
Children:
2b03a62
Parents:
35b8f48a
git-author:
Gerardo Puga <glpuga@…> (06/10/10 13:10:00)
git-committer:
Gedare Bloom <gedare@…> (01/09/14 14:44:14)
Message:

PR 1548: ERC32 console stops working when UART error flags are set

Problem:

The console works fine when only transmitting data from the ERC32, but stops
working after a while when receiving data.

"Stops working" means, bytes are neither sent nor received from the UART, but
the rest of the system keeps functioning (task are executing, the operative
system is responsive, etc).

Context:

  • When an RX error occurs, the ERC32 UARTS stop generating RX/TX interrupts

until the corresponding error flag in the UART_STATUS are cleared.

  • The console.c code currently cleans the error flags from the console_isr_x

subroutines, but those are NOT called when an RX error occurs. Thus the error
flag is never cleaned and then the UARTs stop generating interrupts
indefinitely.

  • The ERC32 UARTs generate a different interrupt when an RX error occurs.

Fixed by:

  • Adding a third interrupt service routine console_isr_error to handle the

UART_ERROR trap. This isr cleans the error flags of the channels.

  • Cleaning the error flags manually just after having initialized the interrupt

vectors. This is because if the error flag was already set by the time the
interrupt vectors are configured, the interrupts might never be called.

File:
1 edited

Legend:

Unmodified
Added
Removed
  • c/src/lib/libbsp/sparc/erc32/console/erc32_console.c

    r35b8f48a r78c84df  
    175175}
    176176
     177static void erc32_console_isr_error(
     178  rtems_vector_number vector
     179)
     180{
     181  int UStat;
     182
     183  UStat = ERC32_MEC.UART_Status;
     184
     185  if (UStat & ERC32_MEC_UART_STATUS_ERRA) {
     186    ERC32_MEC.UART_Status = ERC32_MEC_UART_STATUS_CLRA;
     187    ERC32_MEC.Control = ERC32_MEC.Control;
     188  }
     189
     190  if (UStat & ERC32_MEC_UART_STATUS_ERRB) {
     191    ERC32_MEC.UART_Status = ERC32_MEC_UART_STATUS_CLRB;
     192    ERC32_MEC.Control = ERC32_MEC.Control;
     193  }
     194
     195  ERC32_Clear_interrupt( ERC32_INTERRUPT_UART_ERROR );
     196}
     197
    177198static void erc32_console_isr_a(
    178199  rtems_vector_number vector
     
    305326    set_vector(erc32_console_isr_a, CONSOLE_UART_A_TRAP, 1);
    306327    set_vector(erc32_console_isr_b, CONSOLE_UART_B_TRAP, 1);
     328    set_vector(erc32_console_isr_error, CONSOLE_UART_ERROR_TRAP, 1);
    307329  #endif
    308 }
     330
     331   /* Clear any previous error flags */
     332   ERC32_MEC.UART_Status = ERC32_MEC_UART_STATUS_CLRA;
     333   ERC32_MEC.UART_Status = ERC32_MEC_UART_STATUS_CLRB;
     334}
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