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40 lines
1.8 KiB
Markdown
40 lines
1.8 KiB
Markdown
---
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layout: post
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title: "GPhoto2 fails to connect to Canon EOS 20D"
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date: 2015-03-12 18:43:21 +0100
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comments: true
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categories:
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---
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For the past few months, [Digikam](https://www.digikam.org/)
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(and the underlying [GPhoto2](http://gphoto.sourceforge.net/) library)
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failed to connect to my Canon EOS 20D camera:
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```
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canon/canon/usb.c (2): Initializing the (USB) camera.
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canon/canon/usb.c (2): canon_usb_camera_init()
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canon/canon/usb.c (2): canon_usb_identify: USB ID match 0x04a9:0x30eb (model name "Canon:EOS 20D (normal mode)")
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gp_context_status (2): Detected a 'Canon:EOS 20D (normal mode)'.
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Detected a 'Canon:EOS 20D (normal mode)'.
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gp_port_usb_msg_read (3): Reading message (request=0xc value=0x55 index=0x0 size=1=0x1)...
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gp_port_usb_msg_read (3): Read 0 = 0x0 out of 1 bytes USB message (request=0xc value=0x55 index=0x0 size=1=0x1) (empty hexdump of empty buffer)
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gp_context_error (0): Could not establish initial contact with camera
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*** Error ***
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Could not establish initial contact with camera
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gp_port_close (2): Closing port...
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gp_context_error (0): An error occurred in the io-library ('Unknown error'): No error description available
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```
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Upgrading various components of my system did not help, so I ended up
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suspecting a possible issue with the USB stack, which prompted a
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[major OS upgrade]({% post_url 2015-02-18-upgrading-to-freebsd-10-1-release %})
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from which I am still slowly recovering.
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It turned out that the upgrade did not help. Further investigation and
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debugging finally allowed me to zero in on the cause of the problem,
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which turned out to be a bug in libgphoto2... which coincidentally
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got [fixed](http://sourceforge.net/p/gphoto/code/15384/)
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hours before I identified it on my own.
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