Messages in this thread Patch in this message | | | From | Boqun Feng <> | Subject | [PATCH v4 09/11] HID: hyperv: Use VMBUS_RING_SIZE() for ringbuffer sizes | Date | Wed, 16 Sep 2020 11:48:15 +0800 |
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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@gmail.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Michael Kelley <mikelley@microsoft.com> --- Michael and Jiri,
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/hid/hid-hyperv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c index 0b6ee1dee625..978ee2aab2d4 100644 --- a/drivers/hid/hid-hyperv.c +++ b/drivers/hid/hid-hyperv.c @@ -104,8 +104,8 @@ struct synthhid_input_report { #pragma pack(pop) -#define INPUTVSC_SEND_RING_BUFFER_SIZE (40 * 1024) -#define INPUTVSC_RECV_RING_BUFFER_SIZE (40 * 1024) +#define INPUTVSC_SEND_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024) +#define INPUTVSC_RECV_RING_BUFFER_SIZE VMBUS_RING_SIZE(36 * 1024) enum pipe_prot_msg_type { -- 2.28.0
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