Hello Albert,
Albert Aribaud wrote:
Wolfgang (and others who can/want),
Please test this patch; it should add a complete barrier to make sure that all fixups are written to RAM before jumping there, and that no remnants subsist of the old unfixed code in the instruction paths. However, I cannot even do basic testing on it as I have no 1136 board, so I cannot rule out even basic mistakes.
When this works I'll do a proper [PATCH].
Amicalement, Albert.
diff --git a/arch/arm/cpu/arm1136/start.S b/arch/arm/cpu/arm1136/start.S index 8b63192..f49f1de 100644 --- a/arch/arm/cpu/arm1136/start.S +++ b/arch/arm/cpu/arm1136/start.S @@ -257,6 +257,11 @@ fixloop: add r2, r2, #4 cmp r2, r3 bne fixloop
- /* fixups done, cleanup caches if used and prefetch buffer */
- mov r3, #0
- mcr p15, 0, r3, c7, c10, 4 /* data synchronization barrier */
- mcr p15, 0, r3, c7, c5, 0 /* invalidate instruction cache */
- mcr p15, 0, r3, c7, c5, 4 /* flush prefetch buffer */
#endif #endif /* #ifndef CONFIG_SKIP_RELOCATE_UBOOT */
Actually I tried an identically patch, but didn;t help :-(
But as reading in the arm manual such a memory barrier should not be bad here ...
BTW:
I had a fix for this problem, but I completly not understand what it has to do with relocation (if it really is a problem introduced through relocation ...), nor why a flush_cache helps here, because dcache is off and only icache is on ...
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index f44fc4e..3e326ac 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -203,6 +203,8 @@ static inline void ehci_invalidate_dcache(struct QH *qh) static int handshake(uint32_t *ptr, uint32_t mask, uint32_t done, int usec) { uint32_t result; + + flush_cache(0, 0); do { result = ehci_readl(ptr); if (result == ~(uint32_t)0)
and the "usb read 80000000 0 1000" command works fine ...
Maybe Icache flush dosen;t work because the "ARM1136 Errata 411920 Invalidate Instruction Cache operation can fail" interferes here?
bye, Heiko