uas: fix super speed bMaxPacketSize0
diff mbox series

Message ID 20200117062710.25102-1-kraxel@redhat.com
State New
Headers show
Series
  • uas: fix super speed bMaxPacketSize0
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Commit Message

Gerd Hoffmann Jan. 17, 2020, 6:27 a.m. UTC
For usb2 bMaxPacketSize0 is "n", for usb3 it is "1 << n",
so it must be 9 not 64 ...

Reported-by: fys@fysnet.net
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/dev-uas.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Philippe Mathieu-Daudé Jan. 17, 2020, 7:06 a.m. UTC | #1
On 1/17/20 7:27 AM, Gerd Hoffmann wrote:
> For usb2 bMaxPacketSize0 is "n", for usb3 it is "1 << n",
> so it must be 9 not 64 ...

Maybe add in description:

 From "Universal Serial Bus 3.1 Specification":

   If the device is operating at Gen X speed, the bMaxPacketSize0
   field shall be set to 09H indicating a 512-byte maximum packet.
   An Enhanced SuperSpeed device shall not support any other maximum
   packet sizes for the default control pipe (endpoint 0) control
   endpoint.

We now announce a 512-byte maximum packet.

Fixes: 89a453d4a5c

> Reported-by: fys@fysnet.net

https://wiki.qemu.org/Contribute/SubmitAPatch#Patch_emails_must_include_a_Signed-off-by:_line

"Please use your real name to sign a patch (not an alias or acronym)."

OK this is not about the author name but reporter name.

Gerd, I think you we use 'Reported-by: Benjamin David Lunt 
<fys@fysnet.net>' instead, which was previously used in commit 
9da82227caa7 (except if Ben refuses obviously).

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>   hw/usb/dev-uas.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/usb/dev-uas.c b/hw/usb/dev-uas.c
> index 6d6d1073b907..1bc4dd4fafb8 100644
> --- a/hw/usb/dev-uas.c
> +++ b/hw/usb/dev-uas.c
> @@ -303,7 +303,7 @@ static const USBDescDevice desc_device_high = {
>   
>   static const USBDescDevice desc_device_super = {
>       .bcdUSB                        = 0x0300,
> -    .bMaxPacketSize0               = 64,
> +    .bMaxPacketSize0               = 9,
>       .bNumConfigurations            = 1,
>       .confs = (USBDescConfig[]) {
>           {
>

Patch
diff mbox series

diff --git a/hw/usb/dev-uas.c b/hw/usb/dev-uas.c
index 6d6d1073b907..1bc4dd4fafb8 100644
--- a/hw/usb/dev-uas.c
+++ b/hw/usb/dev-uas.c
@@ -303,7 +303,7 @@  static const USBDescDevice desc_device_high = {
 
 static const USBDescDevice desc_device_super = {
     .bcdUSB                        = 0x0300,
-    .bMaxPacketSize0               = 64,
+    .bMaxPacketSize0               = 9,
     .bNumConfigurations            = 1,
     .confs = (USBDescConfig[]) {
         {