| Message ID | 1327570411-20432-1-git-send-email-avi@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 26/01/2012 10:33, Avi Kivity wrote: > The memory API returns -1 on unassigned reads, different from the original > in exec.c, which returned zero. Isn't this return value platform specific? > This breaks grlib_uart; apparently some users depend on it. > > Fix by returning zero; however if reading from the uart is legal, then > it should be modified to accept reads. > That's right, grlib_uart depends on it because I took the easy (lazy?) way. I will send a patch to handle reads to UART's registers.
On 01/26/2012 01:31 PM, Fabien Chouteau wrote: > On 26/01/2012 10:33, Avi Kivity wrote: > > The memory API returns -1 on unassigned reads, different from the original > > in exec.c, which returned zero. > > Isn't this return value platform specific? Maybe (and I think ~0 is the common one); the patch just restores the previous behaviour. > > > This breaks grlib_uart; apparently some users depend on it. > > > > Fix by returning zero; however if reading from the uart is legal, then > > it should be modified to accept reads. > > > > That's right, grlib_uart depends on it because I took the easy (lazy?) > way. I will send a patch to handle reads to UART's registers. Definitely that's the best way to fix the problem.
diff --git a/memory.c b/memory.c index ee4c98a..afc12dc 100644 --- a/memory.c +++ b/memory.c @@ -917,7 +917,7 @@ static uint64_t memory_region_dispatch_read1(MemoryRegion *mr, uint64_t data = 0; if (!memory_region_access_valid(mr, addr, size, false)) { - return -1U; /* FIXME: better signalling */ + return 0; /* FIXME: better signalling */ } if (!mr->ops->read) {
The memory API returns -1 on unassigned reads, different from the original in exec.c, which returned zero. This breaks grlib_uart; apparently some users depend on it. Fix by returning zero; however if reading from the uart is legal, then it should be modified to accept reads. Signed-off-by: Avi Kivity <avi@redhat.com> --- memory.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)