| Message ID | ae5ca43a-1ccd-b1fd-c699-f9f1d4f96dc3@edgarthier.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Edgar, Thank you for the patch respin. I'm still a bit concerned about that -ENOMEM though: On 06/10/17 11:34, Edgar Thier wrote: > > Use flags the device exposes for UVC controls. > This allows the device to define which property flags are set. > > Since some cameras offer auto-adjustments for properties (e.g. auto-gain), > the values of other properties (e.g. gain) can change in the camera. > Examining the flags ensures that the driver is aware of such properties. > > Signed-off-by: Edgar Thier <info@edgarthier.net> > --- > drivers/media/usb/uvc/uvc_ctrl.c | 56 +++++++++++++++++++++++++++------------- > 1 file changed, 38 insertions(+), 18 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index 20397ab..5091086 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1630,6 +1630,41 @@ static void uvc_ctrl_fixup_xu_info(struct uvc_device *dev, > } > > /* > + * Retrieve flags for a given control > + */ > +static int uvc_ctrl_get_flags(struct uvc_device *dev, const struct uvc_control *ctrl, > + const struct uvc_control_info *info) > +{ > + u8 *data; > + int ret = 0; > + int flags = 0; > + > + data = kmalloc(2, GFP_KERNEL); > + if (data == NULL) > + return -ENOMEM; > + > + ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum, > + info->selector, data, 1); > + if (ret < 0) { > + uvc_trace(UVC_TRACE_CONTROL, > + "GET_INFO failed on control %pUl/%u (%d).\n", > + info->entity, info->selector, ret); > + } else { > + flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX > + | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF > + | (data[0] & UVC_CONTROL_CAP_GET ? > + UVC_CTRL_FLAG_GET_CUR : 0) > + | (data[0] & UVC_CONTROL_CAP_SET ? > + UVC_CTRL_FLAG_SET_CUR : 0) > + | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ? > + UVC_CTRL_FLAG_AUTO_UPDATE : 0); > + } > + kfree(data); > + return flags; > +} > + > + (Minor nit) There's a double blank line there ... > +/* > * Query control information (size and flags) for XU controls. > */ > static int uvc_ctrl_fill_xu_info(struct uvc_device *dev, > @@ -1659,24 +1694,7 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev, > > info->size = le16_to_cpup((__le16 *)data); > > - /* Query the control information (GET_INFO) */ > - ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum, > - info->selector, data, 1); > - if (ret < 0) { > - uvc_trace(UVC_TRACE_CONTROL, > - "GET_INFO failed on control %pUl/%u (%d).\n", > - info->entity, info->selector, ret); > - goto done; > - } > - > - info->flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX > - | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF > - | (data[0] & UVC_CONTROL_CAP_GET ? > - UVC_CTRL_FLAG_GET_CUR : 0) > - | (data[0] & UVC_CONTROL_CAP_SET ? > - UVC_CTRL_FLAG_SET_CUR : 0) > - | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ? > - UVC_CTRL_FLAG_AUTO_UPDATE : 0); In this original code : info->flags is set based on the flags. If the higher kmalloc failed, we wouldn't get here - and an error would have already been returned to the caller. > + info->flags = uvc_ctrl_get_flags(dev, ctrl, info); But now ... info->flags could be set to an error return code if uvc_ctrl_get_flags fails. That error code is not checked anywhere and could be mis-interpreted as 'real (invalid) flags' in other code.... And at no point - have we presented an error message to state that these flags are now set ... but completely invalid. > uvc_ctrl_fixup_xu_info(dev, ctrl, info); > > @@ -1902,6 +1920,8 @@ static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl, > goto done; > } > > + ctrl->info.flags = uvc_ctrl_get_flags(dev, ctrl, info); > + And again here of course - now ctrl->info.flags could be set to -ENOMEM, or rather -12 ... 0x(FFFFFFFF)FFFFFFF4 > ctrl->initialized = 1; > > uvc_trace(UVC_TRACE_CONTROL, "Added control %pUl/%u to device %s " Regards Kieran
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index 20397ab..5091086 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -1630,6 +1630,41 @@ static void uvc_ctrl_fixup_xu_info(struct uvc_device *dev, } /* + * Retrieve flags for a given control + */ +static int uvc_ctrl_get_flags(struct uvc_device *dev, const struct uvc_control *ctrl, + const struct uvc_control_info *info) +{ + u8 *data; + int ret = 0; + int flags = 0; + + data = kmalloc(2, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum, + info->selector, data, 1); + if (ret < 0) { + uvc_trace(UVC_TRACE_CONTROL, + "GET_INFO failed on control %pUl/%u (%d).\n", + info->entity, info->selector, ret); + } else { + flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX + | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF + | (data[0] & UVC_CONTROL_CAP_GET ? + UVC_CTRL_FLAG_GET_CUR : 0) + | (data[0] & UVC_CONTROL_CAP_SET ? + UVC_CTRL_FLAG_SET_CUR : 0) + | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ? + UVC_CTRL_FLAG_AUTO_UPDATE : 0); + } + kfree(data); + return flags; +} + + +/* * Query control information (size and flags) for XU controls. */ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev, @@ -1659,24 +1694,7 @@ static int uvc_ctrl_fill_xu_info(struct uvc_device *dev, info->size = le16_to_cpup((__le16 *)data); - /* Query the control information (GET_INFO) */ - ret = uvc_query_ctrl(dev, UVC_GET_INFO, ctrl->entity->id, dev->intfnum, - info->selector, data, 1); - if (ret < 0) { - uvc_trace(UVC_TRACE_CONTROL, - "GET_INFO failed on control %pUl/%u (%d).\n", - info->entity, info->selector, ret); - goto done; - } - - info->flags = UVC_CTRL_FLAG_GET_MIN | UVC_CTRL_FLAG_GET_MAX - | UVC_CTRL_FLAG_GET_RES | UVC_CTRL_FLAG_GET_DEF - | (data[0] & UVC_CONTROL_CAP_GET ? - UVC_CTRL_FLAG_GET_CUR : 0) - | (data[0] & UVC_CONTROL_CAP_SET ? - UVC_CTRL_FLAG_SET_CUR : 0) - | (data[0] & UVC_CONTROL_CAP_AUTOUPDATE ? - UVC_CTRL_FLAG_AUTO_UPDATE : 0); + info->flags = uvc_ctrl_get_flags(dev, ctrl, info); uvc_ctrl_fixup_xu_info(dev, ctrl, info); @@ -1902,6 +1920,8 @@ static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl, goto done; } + ctrl->info.flags = uvc_ctrl_get_flags(dev, ctrl, info); + ctrl->initialized = 1; uvc_trace(UVC_TRACE_CONTROL, "Added control %pUl/%u to device %s "
Use flags the device exposes for UVC controls. This allows the device to define which property flags are set. Since some cameras offer auto-adjustments for properties (e.g. auto-gain), the values of other properties (e.g. gain) can change in the camera. Examining the flags ensures that the driver is aware of such properties. Signed-off-by: Edgar Thier <info@edgarthier.net> --- drivers/media/usb/uvc/uvc_ctrl.c | 56 +++++++++++++++++++++++++++------------- 1 file changed, 38 insertions(+), 18 deletions(-)