[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <MW2PR2101MB105277B76109C6C25654E077D7340@MW2PR2101MB1052.namprd21.prod.outlook.com>
Date: Sun, 27 Sep 2020 00:10:47 +0000
From: Michael Kelley <mikelley@...rosoft.com>
To: Boqun Feng <boqun.feng@...il.com>,
"linux-hyperv@...r.kernel.org" <linux-hyperv@...r.kernel.org>,
"linux-input@...r.kernel.org" <linux-input@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>
CC: KY Srinivasan <kys@...rosoft.com>,
Haiyang Zhang <haiyangz@...rosoft.com>,
Stephen Hemminger <sthemmin@...rosoft.com>,
Wei Liu <wei.liu@...nel.org>, Jiri Kosina <jikos@...nel.org>,
Benjamin Tissoires <benjamin.tissoires@...hat.com>,
Dmitry Torokhov <dmitry.torokhov@...il.com>,
"David S. Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>,
"James E.J. Bottomley" <jejb@...ux.ibm.com>,
"Martin K. Petersen" <martin.petersen@...cle.com>,
"will@...nel.org" <will@...nel.org>,
"ardb@...nel.org" <ardb@...nel.org>,
"arnd@...db.de" <arnd@...db.de>,
"catalin.marinas@....com" <catalin.marinas@....com>,
"Mark.Rutland@....com" <Mark.Rutland@....com>,
"maz@...nel.org" <maz@...nel.org>
Subject: RE: [PATCH v4 08/11] Input: hyperv-keyboard: Use VMBUS_RING_SIZE()
for ringbuffer sizes
From: Boqun Feng <boqun.feng@...il.com> Sent: Tuesday, September 15, 2020 8:48 PM
>
> For a Hyper-V vmbus, the size of the ringbuffer has two requirements:
>
> 1) it has to take one PAGE_SIZE for the header
>
> 2) it has to be PAGE_SIZE aligned so that double-mapping can work
>
> VMBUS_RING_SIZE() could calculate a correct ringbuffer size which
> fulfills both requirements, therefore use it to make sure vmbus work
> when PAGE_SIZE != HV_HYP_PAGE_SIZE (4K).
>
> Note that since the argument for VMBUS_RING_SIZE() is the size of
> payload (data part), so it will be minus 4k (the size of header when
> PAGE_SIZE = 4k) than the original value to keep the ringbuffer total
> size unchanged when PAGE_SIZE = 4k.
>
> Signed-off-by: Boqun Feng <boqun.feng@...il.com>
> Cc: Michael Kelley <mikelley@...rosoft.com>
> Cc: Dmitry Torokhov <dmitry.torokhov@...il.com>
> ---
> Michael and Dmitry,
>
> I change the code because of a problem I found:
>
> https://lore.kernel.org/lkml/20200914084600.GA45838@debian-boqun.qqnc3lrjykvubdpftowmye0fmh.lx.internal.cloudapp.net/
>
> , so I drop your Reviewed-by or Acked-by tag. If the update version
> looks good to you, may I add your tag again? Thanks in advance, and
> apologies for the inconvenience.
>
> Regards,
> Boqun
>
> drivers/input/serio/hyperv-keyboard.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
> index df4e9f6f4529..1a7b72a9016d 100644
> --- a/drivers/input/serio/hyperv-keyboard.c
> +++ b/drivers/input/serio/hyperv-keyboard.c
> @@ -75,8 +75,8 @@ struct synth_kbd_keystroke {
>
> #define HK_MAXIMUM_MESSAGE_SIZE 256
>
> -#define KBD_VSC_SEND_RING_BUFFER_SIZE (40 * 1024)
> -#define KBD_VSC_RECV_RING_BUFFER_SIZE (40 * 1024)
> +#define KBD_VSC_SEND_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024)
> +#define KBD_VSC_RECV_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024)
>
> #define XTKBD_EMUL0 0xe0
> #define XTKBD_EMUL1 0xe1
> --
> 2.28.0
Reviewed-by: Michael Kelley <mikelley@...rosoft.com>
Powered by blists - more mailing lists