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author | Tomasz Moń <desowin@gmail.com> | 2011-12-21 14:56:22 +0000 |
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committer | Tomasz Moń <desowin@gmail.com> | 2011-12-21 14:56:22 +0000 |
commit | 37f4dfc2597e98c7aa4922c1b32b2337c18a2ca6 (patch) | |
tree | de78aa8912cd8dcf90c9cb76bfa8db452c0f9270 /firmware/target/arm/tms320dm320/system-dm320.c | |
parent | 3aced71e541d66b3f7051294ea58a93ec5a22d3f (diff) | |
download | rockbox-37f4dfc2597e98c7aa4922c1b32b2337c18a2ca6.tar.gz rockbox-37f4dfc2597e98c7aa4922c1b32b2337c18a2ca6.zip |
TMS320DM320: Prevent lockup in udelay() when this function is called with interrupts disabled.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31392 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'firmware/target/arm/tms320dm320/system-dm320.c')
-rw-r--r-- | firmware/target/arm/tms320dm320/system-dm320.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/firmware/target/arm/tms320dm320/system-dm320.c b/firmware/target/arm/tms320dm320/system-dm320.c index 5d7872f2bc..741516a950 100644 --- a/firmware/target/arm/tms320dm320/system-dm320.c +++ b/firmware/target/arm/tms320dm320/system-dm320.c | |||
@@ -412,6 +412,9 @@ void set_cpu_frequency(long frequency) | |||
412 | } | 412 | } |
413 | #endif | 413 | #endif |
414 | 414 | ||
415 | /* | ||
416 | * Waits for specified amount of microseconds | ||
417 | */ | ||
415 | void udelay(int usec) { | 418 | void udelay(int usec) { |
416 | unsigned short count = IO_TIMER1_TMCNT; | 419 | unsigned short count = IO_TIMER1_TMCNT; |
417 | unsigned short stop; | 420 | unsigned short stop; |
@@ -432,16 +435,28 @@ void udelay(int usec) { | |||
432 | stop -= tmp; | 435 | stop -= tmp; |
433 | } | 436 | } |
434 | 437 | ||
438 | /* | ||
439 | * Status in IO_INTC_IRQ0 is changed even when interrupts are | ||
440 | * masked. If IRQ_TIMER1 bit in IO_INTC_IRQ0 is set to 0, then | ||
441 | * there is pending current_tick update. | ||
442 | * | ||
443 | * Relaying solely on current_tick value when interrupts are disabled | ||
444 | * can lead to lockup. | ||
445 | * Interrupt status bit check below is used to prevent this lockup. | ||
446 | */ | ||
447 | |||
435 | if (stop < count) | 448 | if (stop < count) |
436 | { | 449 | { |
437 | /* udelay will end after counter reset (tick) */ | 450 | /* udelay will end after counter reset (tick) */ |
438 | while ((IO_TIMER1_TMCNT < stop) || | 451 | while ((IO_TIMER1_TMCNT < stop) || |
439 | (current_tick == prev_tick)); /* ensure new tick */ | 452 | ((current_tick == prev_tick) /* ensure new tick */ && |
453 | (IO_INTC_IRQ0 & IRQ_TIMER1))); /* prevent lock */ | ||
440 | } | 454 | } |
441 | else | 455 | else |
442 | { | 456 | { |
443 | /* udelay will end before counter reset (tick) */ | 457 | /* udelay will end before counter reset (tick) */ |
444 | while ((IO_TIMER1_TMCNT < stop) && (current_tick == prev_tick)); | 458 | while ((IO_TIMER1_TMCNT < stop) && |
459 | ((current_tick == prev_tick) && (IO_INTC_IRQ0 & IRQ_TIMER1))); | ||
445 | } | 460 | } |
446 | } | 461 | } |
447 | 462 | ||