mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-04-12 06:49:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

fbdev: hyperv_fb: Allow graceful removal of framebuffer

Browse Source 
When a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to
release the framebuffer forcefully. If this framebuffer is in use it
produce the following WARN and hence this framebuffer is never released.

[   44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40
< snip >
[   44.111289] Call Trace:
[   44.111290]  <TASK>
[   44.111291]  ? show_regs+0x6c/0x80
[   44.111295]  ? __warn+0x8d/0x150
[   44.111298]  ? framebuffer_release+0x2c/0x40
[   44.111300]  ? report_bug+0x182/0x1b0
[   44.111303]  ? handle_bug+0x6e/0xb0
[   44.111306]  ? exc_invalid_op+0x18/0x80
[   44.111308]  ? asm_exc_invalid_op+0x1b/0x20
[   44.111311]  ? framebuffer_release+0x2c/0x40
[   44.111313]  ? hvfb_remove+0x86/0xa0 [hyperv_fb]
[   44.111315]  vmbus_remove+0x24/0x40 [hv_vmbus]
[   44.111323]  device_remove+0x40/0x80
[   44.111325]  device_release_driver_internal+0x20b/0x270
[   44.111327]  ? bus_find_device+0xb3/0xf0

Fix this by moving the release of framebuffer and assosiated memory
to fb_ops.fb_destroy function, so that framebuffer framework handles
it gracefully.

While we fix this, also replace manual registrations/unregistration of
framebuffer with devm_register_framebuffer.

Fixes: 68a2d20b79b1 ("drivers/video: add Hyper-V Synthetic Video Frame Buffer Driver")

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com>
This commit is contained in:
Saurabh Sengar 2025-03-01 08:16:31 -08:00 committed by Wei Liu
parent f5e728a50b
commit ea2f45ab0e
1 changed files with 15 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/video/fbdev/hyperv_fb.c
View File

@ -282,6 +282,8 @@ static uint screen_depth;
static uint screen_fb_size;
static uint dio_fb_size; /* FB size for deferred IO */
static void hvfb_putmem(struct fb_info *info);
/* Send message to Hyper-V host */
static inline int synthvid_send(struct hv_device *hdev,
struct synthvid_msg *msg)
@ -862,6 +864,17 @@ static void hvfb_ops_damage_area(struct fb_info *info, u32 x, u32 y, u32 width,
hvfb_ondemand_refresh_throttle(par, x, y, width, height);
}
/*
* fb_ops.fb_destroy is called by the last put_fb_info() call at the end
* of unregister_framebuffer() or fb_release(). Do any cleanup related to
* framebuffer here.
*/
static void hvfb_destroy(struct fb_info *info)
{
hvfb_putmem(info);
framebuffer_release(info);
}
/*
* TODO: GEN1 codepaths allocate from system or DMA-able memory. Fix the
* driver to use the _SYSMEM_ or _DMAMEM_ helpers in these cases.
@ -877,6 +890,7 @@ static const struct fb_ops hvfb_ops = {
.fb_set_par = hvfb_set_par,
.fb_setcolreg = hvfb_setcolreg,
.fb_blank = hvfb_blank,
.fb_destroy = hvfb_destroy,
};
/* Get options from kernel paramenter "video=" */
@ -1178,7 +1192,7 @@ static int hvfb_probe(struct hv_device *hdev,
if (ret)
goto error;
ret = register_framebuffer(info);
ret = devm_register_framebuffer(&hdev->device, info);
if (ret) {
pr_err("Unable to register framebuffer\n");
goto error;
@ -1226,14 +1240,10 @@ static void hvfb_remove(struct hv_device *hdev)
fb_deferred_io_cleanup(info);
unregister_framebuffer(info);
cancel_delayed_work_sync(&par->dwork);
vmbus_close(hdev->channel);
hv_set_drvdata(hdev, NULL);
hvfb_putmem(info);
framebuffer_release(info);
}
static int hvfb_suspend(struct hv_device *hdev)