Re: [Qemu-devel] [PATCH RFC] ps2: set the keybord output buffer size as the same as kernel

[Gonglei (Arei)]

Hi,

> -----Original Message-----
> From: Gonglei (Arei)
> Sent: Thursday, April 17, 2014 9:16 PM
> To: address@hidden
> Cc: address@hidden; address@hidden; Huangweidong (C); Gonglei
> (Arei)
> Subject: [PATCH RFC] ps2: set the keybord output buffer size as the same as
> kernel
> 
> From: Gonglei <address@hidden>
> 
> According to the PS/2 Mouse/Keyboard Protocol, the keyboard outupt buffer
> size
> is 16 bytes. And the PS2_QUEUE_SIZE 256 was introduced in Qemu from the
> very
> beginning.
> 
> When I started a  redhat5.6 32bit guest, meanwhile tapped the keyboard as
> quickly as
> possible, the screen would show me "i8042.c: No controller found". As a 
> result,
> I couldn't use the keyboard in the VNC client.
> 
> Previous discussion about the issue in maillist:
> http://thread.gmane.org/gmane.comp.emulators.qemu/43294/focus=47180
> 
> This patch has been tested on redhat5.6 32-bit/suse11sp3 64-bit guests.
> More easy meathod to reproduce:
> 1.boot a guest with libvirt.
> 2.connect to VNC client.
> 3.as you see the BIOS, bootloader, Linux booting, run the follow simply shell
> script:
> for((i=0;i<10000000;i++)) do virsh send-key redhat5.6 KEY_A; done
> 
> Actual results:
> dmesg show "i8042.c: No controller found." And the keyboard is out of work.
> 
> Signed-off-by: Gonglei <address@hidden>
> ---
>  hw/input/ps2.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/input/ps2.c b/hw/input/ps2.c
> index 3412079..a754fef 100644
> --- a/hw/input/ps2.c
> +++ b/hw/input/ps2.c
> @@ -71,7 +71,7 @@
>  #define MOUSE_STATUS_ENABLED    0x20
>  #define MOUSE_STATUS_SCALE21    0x10
> 
> -#define PS2_QUEUE_SIZE 256
> +#define PS2_QUEUE_SIZE 16     /* Keyboard output buffer size */
> 
>  typedef struct {
>      uint8_t data[PS2_QUEUE_SIZE];
> @@ -137,7 +137,7 @@ void ps2_queue(void *opaque, int b)
>      PS2State *s = (PS2State *)opaque;
>      PS2Queue *q = &s->queue;
> 
> -    if (q->count >= PS2_QUEUE_SIZE)
> +    if (q->count >= PS2_QUEUE_SIZE - 1)
>          return;
>      q->data[q->wptr] = b;
>      if (++q->wptr == PS2_QUEUE_SIZE)
> @@ -375,7 +375,7 @@ static void ps2_mouse_event(void *opaque,
>      }
> 
>      if (!(s->mouse_status & MOUSE_STATUS_REMOTE) &&
> -        (s->common.queue.count < (PS2_QUEUE_SIZE - 16))) {
> +        (s->common.queue.count < PS2_QUEUE_SIZE)) {
>          for(;;) {
>              /* if not remote, send event. Multiple events are sent if
>                 too big deltas */
> --
> 1.6.0.2
> 

Ping...
Any comments will be appreciated.


Best regards,
-Gonglei