From: Pawel Laszczak <[email protected]>
Patch adds extra checking for bInterval passed by configfs.
The 5.6.4 chapter of USB Specification (rev. 2.0) say:
"A high-bandwidth endpoint must specify a period of 1x125 µs
(i.e., a bInterval value of 1)."
The issue was observed during testing UVC class on CV.
I treat this change as improvement because we can control
bInterval by configfs.
Signed-off-by: Pawel Laszczak <[email protected]>
---
drivers/usb/gadget/function/f_uvc.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
index 44b4352a2676..5d62720bb9e1 100644
--- a/drivers/usb/gadget/function/f_uvc.c
+++ b/drivers/usb/gadget/function/f_uvc.c
@@ -631,6 +631,12 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
+ /* A high-bandwidth endpoint must specify a bInterval value of 1 */
+ if (max_packet_mult > 1)
+ uvc_hs_streaming_ep.bInterval = 1;
+ else
+ uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
+
uvc_hs_streaming_ep.wMaxPacketSize =
cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
--
2.25.1
>
>On Fri, Mar 5, 2021 at 12:40 AM Pawel Laszczak <mailto:[email protected]> wrote:
>From: Pawel Laszczak <mailto:[email protected]>
>
>Patch adds extra checking for bInterval passed by configfs.
>The 5.6.4 chapter of USB Specification (rev. 2.0) say:
>"A high-bandwidth endpoint must specify a period of 1x125 µs
>(i.e., a bInterval value of 1)."
>
>The issue was observed during testing UVC class on CV.
>I treat this change as improvement because we can control
>bInterval by configfs.
>
>Signed-off-by: Pawel Laszczak <mailto:[email protected]>
>---
> drivers/usb/gadget/function/f_uvc.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
>diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
>index 44b4352a2676..5d62720bb9e1 100644
>--- a/drivers/usb/gadget/function/f_uvc.c
>+++ b/drivers/usb/gadget/function/f_uvc.c
>@@ -631,6 +631,12 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
> cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
> uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
>
>+ /* A high-bandwidth endpoint must specify a bInterval value of 1 */
>+ if (max_packet_mult > 1)
>+ uvc_hs_streaming_ep.bInterval = 1;
>+ else
>+ uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
>+
>
>There is a "uvc_hs_streaming_ep.bInterval = opts->streaming_interval;" again at below code
>Besides, the default value is 1 for opts->streaming_interval. What the real issue you observed
>at CV test?
>
The issue occurs when I intentionally set:
echo 3072 > functions/$FUNCTION/streaming_maxpacket
echo 4 > functions/$FUNCTION/streaming_interval
Then for CV CH9 TD 9.5: Endpoint Descriptor test it got:
"(Mult = 2)Illegal high speed isochronous endpoint MaxPacketSize : 0x400
(USB: 1.2.78) A High speed Interrupt/Isochronous endpoint must have a MaxPacketSize between
683 and 1024 and bInterval value of 1 when the Mult value is two."
For default value CV passed. Of course, I can fix it by changing streaming_interval, but I thought that
it could be good to have protection against this issue.
Especially since Usb 2 specification say that bInterval must be 1 for high bandwidth endpoints.
Pawel
>Peter
>
> uvc_hs_streaming_ep.wMaxPacketSize =
> cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
> uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
>--
>2.25.1
Peter,
You're right. This patch is wrong. I didn't remove the "uvc_hs_streaming_ep.bInterval"
assignment.
It has been fixed in v2.
Pawel
>>
>>On Fri, Mar 5, 2021 at 12:40 AM Pawel Laszczak <mailto:[email protected]> wrote:
>>From: Pawel Laszczak <mailto:[email protected]>
>>
>>Patch adds extra checking for bInterval passed by configfs.
>>The 5.6.4 chapter of USB Specification (rev. 2.0) say:
>>"A high-bandwidth endpoint must specify a period of 1x125 µs
>>(i.e., a bInterval value of 1)."
>>
>>The issue was observed during testing UVC class on CV.
>>I treat this change as improvement because we can control
>>bInterval by configfs.
>>
>>Signed-off-by: Pawel Laszczak <mailto:[email protected]>
>>---
>> drivers/usb/gadget/function/f_uvc.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>>diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
>>index 44b4352a2676..5d62720bb9e1 100644
>>--- a/drivers/usb/gadget/function/f_uvc.c
>>+++ b/drivers/usb/gadget/function/f_uvc.c
>>@@ -631,6 +631,12 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
>> cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
>> uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
>>
>>+ /* A high-bandwidth endpoint must specify a bInterval value of 1 */
>>+ if (max_packet_mult > 1)
>>+ uvc_hs_streaming_ep.bInterval = 1;
>>+ else
>>+ uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
>>+
>>
>>There is a "uvc_hs_streaming_ep.bInterval = opts->streaming_interval;" again at below code
>>Besides, the default value is 1 for opts->streaming_interval. What the real issue you observed
>>at CV test?
>>
>
>The issue occurs when I intentionally set:
> echo 3072 > functions/$FUNCTION/streaming_maxpacket
> echo 4 > functions/$FUNCTION/streaming_interval
>
>Then for CV CH9 TD 9.5: Endpoint Descriptor test it got:
>"(Mult = 2)Illegal high speed isochronous endpoint MaxPacketSize : 0x400
>(USB: 1.2.78) A High speed Interrupt/Isochronous endpoint must have a MaxPacketSize between
>683 and 1024 and bInterval value of 1 when the Mult value is two."
>
>For default value CV passed. Of course, I can fix it by changing streaming_interval, but I thought that
>it could be good to have protection against this issue.
>Especially since Usb 2 specification say that bInterval must be 1 for high bandwidth endpoints.
>
>Pawel
>
>>Peter
>>
>> uvc_hs_streaming_ep.wMaxPacketSize =
>> cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
>> uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
>>--
>>2.25.1
Thanks,
Pawel Laszczak
Please check whether the problem occurs in this fragment of code:
https://elixir.bootlin.com/linux/latest/source/drivers/usb/cdns3/gadget.c#L2569
zlp_buff is allocated with kzalloc.
Pawel
>>On Fri, Mar 5, 2021 at 12:40 AM Pawel Laszczak <mailto:[email protected]> wrote:
>>From: Pawel Laszczak <mailto:[email protected]>
>>
>>Patch adds extra checking for bInterval passed by configfs.
>>The 5.6.4 chapter of USB Specification (rev. 2.0) say:
>>"A high-bandwidth endpoint must specify a period of 1x125 µs
>>(i.e., a bInterval value of 1)."
>>
>>The issue was observed during testing UVC class on CV.
>>I treat this change as improvement because we can control
>>bInterval by configfs.
>>
>>Signed-off-by: Pawel Laszczak <mailto:[email protected]>
>>---
>> drivers/usb/gadget/function/f_uvc.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>>diff --git a/drivers/usb/gadget/function/f_uvc.c b/drivers/usb/gadget/function/f_uvc.c
>>index 44b4352a2676..5d62720bb9e1 100644
>>--- a/drivers/usb/gadget/function/f_uvc.c
>>+++ b/drivers/usb/gadget/function/f_uvc.c
>>@@ -631,6 +631,12 @@ uvc_function_bind(struct usb_configuration *c, struct usb_function *f)
>> cpu_to_le16(min(opts->streaming_maxpacket, 1023U));
>> uvc_fs_streaming_ep.bInterval = opts->streaming_interval;
>>
>>+ /* A high-bandwidth endpoint must specify a bInterval value of 1 */
>>+ if (max_packet_mult > 1)
>>+ uvc_hs_streaming_ep.bInterval = 1;
>>+ else
>>+ uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
>>+
>>
>>There is a "uvc_hs_streaming_ep.bInterval = opts->streaming_interval;" again at below code
>>Besides, the default value is 1 for opts->streaming_interval. What the real issue you observed
>>at CV test?
>>
>
>The issue occurs when I intentionally set:
> echo 3072 > functions/$FUNCTION/streaming_maxpacket
> echo 4 > functions/$FUNCTION/streaming_interval
>
>Then for CV CH9 TD 9.5: Endpoint Descriptor test it got:
>"(Mult = 2)Illegal high speed isochronous endpoint MaxPacketSize : 0x400
>(USB: 1.2.78) A High speed Interrupt/Isochronous endpoint must have a MaxPacketSize between
>683 and 1024 and bInterval value of 1 when the Mult value is two."
>
>For default value CV passed. Of course, I can fix it by changing streaming_interval, but I thought that
>it could be good to have protection against this issue.
>Especially since Usb 2 specification say that bInterval must be 1 for high bandwidth endpoints.
>
>Pawel
>
>>Peter
>>
>> uvc_hs_streaming_ep.wMaxPacketSize =
>> cpu_to_le16(max_packet_size | ((max_packet_mult - 1) << 11));
>> uvc_hs_streaming_ep.bInterval = opts->streaming_interval;
>>--
>>2.25.1