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![]() The udlfb driver maintained an open count and cleaned up itself when the count reached zero. But the console is also counted in the reference count - so, if the user unplugged the device, the open count would not drop to zero and the driver stayed loaded with console attached. If the user re-plugged the adapter, it would create a device /dev/fb1, show green screen and the access to the console would be lost. The framebuffer subsystem has reference counting on its own - in order to fix the unplug bug, we rely the framebuffer reference counting. When the user unplugs the adapter, we call unregister_framebuffer unconditionally. unregister_framebuffer will unbind the console, wait until all users stop using the framebuffer and then call the fb_destroy method. The fb_destroy cleans up the USB driver. This patch makes the following changes: * Drop dlfb->kref and rely on implicit framebuffer reference counting instead. * dlfb_usb_disconnect calls unregister_framebuffer, the rest of driver cleanup is done in the function dlfb_ops_destroy. dlfb_ops_destroy will be called by the framebuffer subsystem when no processes have the framebuffer open or mapped. * We don't use workqueue during initialization, but initialize directly from dlfb_usb_probe. The workqueue could race with dlfb_usb_disconnect and this racing would produce various kinds of memory corruption. * We use usb_get_dev and usb_put_dev to make sure that the USB subsystem doesn't free the device under us. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> cc: Dave Airlie <airlied@redhat.com> Cc: Bernie Thompson <bernie@plugable.com>, Cc: Ladislav Michl <ladis@linux-mips.org> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> |
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.. | ||
atmel_lcdc.h | ||
aty128.h | ||
broadsheetfb.h | ||
cirrus.h | ||
cvisionppc.h | ||
da8xx-fb.h | ||
display_timing.h | ||
edid.h | ||
gbe.h | ||
hecubafb.h | ||
ili9320.h | ||
imx-ipu-image-convert.h | ||
imx-ipu-v3.h | ||
kyro.h | ||
mach64.h | ||
maxinefb.h | ||
mbxfb.h | ||
metronomefb.h | ||
mipi_display.h | ||
mmp_disp.h | ||
neomagic.h | ||
newport.h | ||
of_display_timing.h | ||
of_videomode.h | ||
omap-panel-data.h | ||
omapfb_dss.h | ||
omapvrfb.h | ||
permedia2.h | ||
platform_lcd.h | ||
pm3fb.h | ||
pmag-ba-fb.h | ||
pmagb-b-fb.h | ||
pxa168fb.h | ||
radeon.h | ||
s1d13xxxfb.h | ||
sa1100fb.h | ||
samsung_fimd.h | ||
sh_mobile_lcdc.h | ||
sisfb.h | ||
sstfb.h | ||
tdfx.h | ||
tgafb.h | ||
trident.h | ||
udlfb.h | ||
uvesafb.h | ||
vga.h | ||
videomode.h | ||
w100fb.h |