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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2018-06-18 13:24:25 +1000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2018-06-18 14:07:21 +1000 |
| commit | 3cca9b869028a3c2ccbb4915fbb64c5746b55081 (patch) | |
| tree | 7ac3e3ba72e438de8a3835b4a1fb8c14c6f9a009 /cf-code/cf-fsi-fw.S | |
| parent | 42593be0cb5cd6bf133ce3897866319f18050bed (diff) | |
| download | cf-fsi-3cca9b869028a3c2ccbb4915fbb64c5746b55081.tar.gz cf-fsi-3cca9b869028a3c2ccbb4915fbb64c5746b55081.zip | |
Do not rely on interrupts on AST2400
It doesn't have the SW interrupt triggers. Use NOP loops
instead to pace ourselves when waiting for arbitration
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'cf-code/cf-fsi-fw.S')
| -rw-r--r-- | cf-code/cf-fsi-fw.S | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/cf-code/cf-fsi-fw.S b/cf-code/cf-fsi-fw.S index 6af7e25..c0ca927 100644 --- a/cf-code/cf-fsi-fw.S +++ b/cf-code/cf-fsi-fw.S @@ -308,9 +308,11 @@ main_loop: #ifdef CONTINUOUS_CLOCKING clock_toggle #else +#ifndef NO_SW_IRQ stop #0x2000 move.w #0x2007,%sr #endif +#endif bra 1b arbitration_request: @@ -318,9 +320,27 @@ arbitration_request: move.b #ARB_ARM_ACK,%a1@(ARB_REG) /* Wait until it's cleared by the host */ -0: move.b %a1@(ARB_REG),%d1 - bne 1f +arb_wait: + move.b %a1@(ARB_REG),%d1 + beq arb_done + +#ifdef NO_SW_IRQ + /* In absence of SW irq, just loop with some NOPs to avoid + * hammering the bus too hard + */ + moveq.l #32,%d0 +0: nop + subq.l #1,%d0 + bne 0b + bra arb_wait +#else + /* Wait, we'll get an interrupt when the host clears it */ + stop #0x2000 + move.w #0x2007,%sr + bra arb_wait +#endif +arb_done: /* Got it, re-load the GPIO caches */ move.l %a5@(0),%DCLK move.l %a4@(0),%DDAT @@ -333,11 +353,6 @@ arbitration_request: /* Back to main loop */ bra main_loop - /* Wait, we'll get an interrupt when the host clears it */ -1: stop #0x2000 - move.w #0x2007,%sr - bra 0b - command_request: /* Clear the command/status register */ moveq.l #0,%d0 |
