On 12/3/25 14:43, Peter Maydell wrote:
On Wed, 12 Mar 2025 at 13:36, Peter Maydell <peter.mayd...@linaro.org> wrote:
On Tue, 11 Mar 2025 at 15:37, Paolo Bonzini <pbonz...@redhat.com> wrote:
The guest does not control whether characters are sent on the UART.
Sending them before the guest happens to boot will now result in a
"guest error" log entry that is only because of timing, even if the
guest _would_ later setup the receiver correctly.
This reverts commit abf2b6a028670bd2890bb3aee7e103fe53e4b0df, apart
from adding the comment.
Cc: Philippe Mathieu-Daudé <phi...@linaro.org>
Cc: Peter Maydell <peter.mayd...@linaro.org>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
hw/char/pl011.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/hw/char/pl011.c b/hw/char/pl011.c
index 23a9db8c57c..efca8baecd7 100644
--- a/hw/char/pl011.c
+++ b/hw/char/pl011.c
@@ -85,7 +85,6 @@ DeviceState *pl011_create(hwaddr addr, qemu_irq irq, Chardev
*chr)
#define CR_OUT1 (1 << 12)
#define CR_RTS (1 << 11)
#define CR_DTR (1 << 10)
-#define CR_RXE (1 << 9)
#define CR_TXE (1 << 8)
#define CR_LBE (1 << 7)
#define CR_UARTEN (1 << 0)
@@ -490,16 +489,9 @@ static int pl011_can_receive(void *opaque)
unsigned fifo_depth = pl011_get_fifo_depth(s);
unsigned fifo_available = fifo_depth - s->read_count;
- if (!(s->cr & CR_UARTEN)) {
- qemu_log_mask(LOG_GUEST_ERROR,
- "PL011 receiving data on disabled UART\n");
- }
- if (!(s->cr & CR_RXE)) {
- qemu_log_mask(LOG_GUEST_ERROR,
- "PL011 receiving data on disabled RX UART\n");
- }
+ /* Should check enable and return 0? */
We decided deliberately not to check the enable and return 0
here, as described in the commit message of abf2b6a028670bd:
we think there's too likely to be existing works-on-QEMU code
out there that doesn't ever set the enable bits.
Otherwise, yes, agreed with the revert.
Oh, and I just realized that the right place to diagnose
"guest didn't enable the UART" would be when it reads/writes
the data register while the enable bits are clear.
Doh, sorry. I wonder how I ended putting this code here... Since I
rebased this a lot, maybe something went wrong. Anyway, I'll post
a fix.
Regards,
Phil.
