FreeCalypso > hg > fc-tourmaline
view cdg-hybrid/sap/gsmcom.pdf @ 220:0ed36de51973
ABB semaphore protection overhaul
The ABB semaphone protection logic that came with TCS211 from TI
was broken in several ways:
* Some semaphore-protected functions were called from Application_Initialize()
context. NU_Obtain_Semaphore() called with NU_SUSPEND fails with
NU_INVALID_SUSPEND in this context, but the return value wasn't checked,
and NU_Release_Semaphore() would be called unconditionally at the end.
The latter call would increment the semaphore count past 1, making the
semaphore no longer binary and thus no longer effective for resource
protection. The fix is to check the return value from NU_Obtain_Semaphore()
and skip the NU_Release_Semaphore() call if the semaphore wasn't properly
obtained.
* Some SPI hardware manipulation was being done before entering the semaphore-
protected critical section. The fix is to reorder the code: first obtain
the semaphore, then do everything else.
* In the corner case of L1/DSP recovery, l1_abb_power_on() would call some
non-semaphore-protected ABB & SPI init functions. The fix is to skip those
calls in the case of recovery.
* A few additional corner cases existed, all of which are fixed by making
ABB semaphore protection 100% consistent for all ABB functions and code paths.
There is still one remaining problem of priority inversion: suppose a low-
priority task calls an ABB function, and some medium-priority task just happens
to preempt right in the middle of that semaphore-protected ABB operation. Then
the high-priority SPI task is locked out for a non-deterministic time until
that medium-priority task finishes its work and goes back to sleep. This
priority inversion problem remains outstanding for now.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Mon, 26 Apr 2021 20:55:25 +0000 |
| parents | 35f7a1dc9f7d |
| children |
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;******************************************************************************** ;*** File : gsmcom.pdf ;*** Creation : Wed Mar 11 09:58:11 CST 2009 ;*** XSLT Processor : Apache Software Foundation / http://xml.apache.org/xalan-j / supports XSLT-Ver: 1 ;*** Copyright : (c) Texas Instruments AG, Berlin Germany 2002 ;******************************************************************************** ;*** Document Type : Service Access Point Specification ;*** Document Name : gsmcom ;*** Document No. : 8443.100.02.008 ;*** Document Date : 2002-10-04 ;*** Document Status: BEING_PROCESSED ;*** Document Author: HM ;******************************************************************************** PRAGMA SRC_FILE_TIME "Thu Nov 29 09:43:26 2007" PRAGMA LAST_MODIFIED "2002-10-04" PRAGMA ID_AND_VERSION "8443.100.02.008" CONST SIM_ORIGINATING_ENTITY 0b000000 ; mask for indicating the originating entity of a cause is SIM CONST ACI_ORIGINATING_ENTITY 0b000001 ; mask for indicating the originating entity of a cause is ACI CONST RLP_ORIGINATING_ENTITY 0b000010 ; mask for indicating the originating entity of a cause is RLP CONST RR_ORIGINATING_ENTITY 0b000011 ; mask for indicating the originating entity of a cause is RR CONST MM_ORIGINATING_ENTITY 0b000100 ; mask for indicating the originating entity of a cause is MM CONST CC_ORIGINATING_ENTITY 0b000101 ; mask for indicating the originating entity of a cause is CC CONST SS_ORIGINATING_ENTITY 0b000110 ; mask for indicating the originating entity of a cause is SS CONST SMSCP_ORIGINATING_ENTITY 0b000111 ; mask for indicating the originating entity of a cause is SMS-CP CONST SMSRP_ORIGINATING_ENTITY 0b001000 ; mask for indicating the originating entity of a cause is SMS-RP CONST SMSTP_ORIGINATING_ENTITY 0b001001 ; mask for indicating the originating entity of a cause is SMS-TP CONST GMM_ORIGINATING_ENTITY 0b001010 ; mask for indicating the originating entity of a cause is GMM CONST SM_ORIGINATING_ENTITY 0b001011 ; mask for indicating the originating entity of a cause is SM CONST FAD_ORIGINATING_ENTITY 0b001100 ; mask for indicating the originating entity of a cause is FAD CONST T30_ORIGINATING_ENTITY 0b001101 ; mask for indicating the originating entity of a cause is T30 CONST GRR_ORIGINATING_ENTITY 0b001110 ; mask for indicating the originating entity of a cause is GRR CONST PPP_ORIGINATING_ENTITY 0b001111 ; mask for indicating the originating entity of a cause is PPP CONST LLC_ORIGINATING_ENTITY 0b010000 ; mask for indicating the originating entity of a cause is LLC CONST SNDCP_ORIGINATING_ENTITY 0b010001 ; mask for indicating the originating entity of a cause is SNDCP CONST PKTIO_ORIGINATING_ENTITY 0b010010 ; mask for indicating the originating entity of a cause is PKTIO CONST PSI_ORIGINATING_ENTITY 0b010011 ; mask for indicating the originating entity of a cause is PSI VALTAB VAL_gsmcom_dummy VAL 0 - 6 "ms originated identifier" VAR gsmcom_dummy "dummy, not used" B VAL @p_gsmcom - VAL_gsmcom_dummy@ ; GSMCOM_DUMMY_REQ 0x80000000 PRIM GSMCOM_DUMMY_REQ 0x80000000 { gsmcom_dummy ; dummy }