| Message ID | 20240201060022.233666-1-mhklinux@outlook.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream, archived |
| Headers | show |
| Series | [1/1] fbdev/hyperv_fb: Fix logic error for Gen2 VMs in hvfb_getmem() | expand |
Hi Am 01.02.24 um 07:00 schrieb mhkelley58@gmail.com: > From: Michael Kelley <mhklinux@outlook.com> > > A recent commit removing the use of screen_info introduced a logic > error. The error causes hvfb_getmem() to always return -ENOMEM > for Generation 2 VMs. As a result, the Hyper-V frame buffer > device fails to initialize. The error was introduced by removing > an "else if" clause, leaving Gen2 VMs to always take the -ENOMEM > error path. > > Fix the problem by removing the error path "else" clause. Gen 2 > VMs now always proceed through the MMIO memory allocation code, > but with "base" and "size" defaulting to 0. Indeed, that's how it was supposed to work. IDK how I didn't notice this bug. Thanks a lot for the fix. > > Fixes: 0aa0838c84da ("fbdev/hyperv_fb: Remove firmware framebuffers with aperture helpers") > Signed-off-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> > --- > drivers/video/fbdev/hyperv_fb.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c > index c26ee6fd73c9..8fdccf033b2d 100644 > --- a/drivers/video/fbdev/hyperv_fb.c > +++ b/drivers/video/fbdev/hyperv_fb.c > @@ -1010,8 +1010,6 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info) > goto getmem_done; > } > pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n"); > - } else { > - goto err1; > } > > /*
On Wed, Jan 31, 2024 at 10:00:22PM -0800, mhkelley58@gmail.com wrote: > From: Michael Kelley <mhklinux@outlook.com> > > A recent commit removing the use of screen_info introduced a logic > error. The error causes hvfb_getmem() to always return -ENOMEM > for Generation 2 VMs. As a result, the Hyper-V frame buffer > device fails to initialize. The error was introduced by removing > an "else if" clause, leaving Gen2 VMs to always take the -ENOMEM > error path. > > Fix the problem by removing the error path "else" clause. Gen 2 > VMs now always proceed through the MMIO memory allocation code, > but with "base" and "size" defaulting to 0. > > Fixes: 0aa0838c84da ("fbdev/hyperv_fb: Remove firmware framebuffers with aperture helpers") > Signed-off-by: Michael Kelley <mhklinux@outlook.com> > --- > drivers/video/fbdev/hyperv_fb.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c > index c26ee6fd73c9..8fdccf033b2d 100644 > --- a/drivers/video/fbdev/hyperv_fb.c > +++ b/drivers/video/fbdev/hyperv_fb.c > @@ -1010,8 +1010,6 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info) > goto getmem_done; > } > pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n"); > - } else { > - goto err1; > } > > /* > -- > 2.25.1 > Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
From: Thomas Zimmermann <tzimmermann@suse.de> Sent: Thursday, February 1, 2024 12:17 AM > > Hi > > Am 01.02.24 um 07:00 schrieb mhkelley58@gmail.com: > > From: Michael Kelley <mhklinux@outlook.com> > > > > A recent commit removing the use of screen_info introduced a logic > > error. The error causes hvfb_getmem() to always return -ENOMEM > > for Generation 2 VMs. As a result, the Hyper-V frame buffer > > device fails to initialize. The error was introduced by removing > > an "else if" clause, leaving Gen2 VMs to always take the -ENOMEM > > error path. > > > > Fix the problem by removing the error path "else" clause. Gen 2 > > VMs now always proceed through the MMIO memory allocation code, > > but with "base" and "size" defaulting to 0. > > Indeed, that's how it was supposed to work. IDK how I didn't notice this > bug. Thanks a lot for the fix. > > > > > Fixes: 0aa0838c84da ("fbdev/hyperv_fb: Remove firmware framebufferswith aperture helpers") > > Signed-off-by: Michael Kelley <mhklinux@outlook.com> > > Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Wei Liu and Helge Deller -- Should this fix go through the Hyper-V tree or the fbdev tree? I'm not aware of a reason that it really matters, but it needs to be one or the other, and sooner rather than later, because the Hyper-V driver is broken starting in 6.8-rc1. Michael > > > --- > > drivers/video/fbdev/hyperv_fb.c | 2 -- > > 1 file changed, 2 deletions(-) > > > > diff --git a/drivers/video/fbdev/hyperv_fb.c > b/drivers/video/fbdev/hyperv_fb.c > > index c26ee6fd73c9..8fdccf033b2d 100644 > > --- a/drivers/video/fbdev/hyperv_fb.c > > +++ b/drivers/video/fbdev/hyperv_fb.c > > @@ -1010,8 +1010,6 @@ static int hvfb_getmem(struct hv_device *hdev, > struct fb_info *info) > > goto getmem_done; > > } > > pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n"); > > - } else { > > - goto err1; > > } > > > > /* >
On 2/9/24 16:23, Michael Kelley wrote: > From: Thomas Zimmermann <tzimmermann@suse.de> Sent: Thursday, February 1, 2024 12:17 AM >> >> Hi >> >> Am 01.02.24 um 07:00 schrieb mhkelley58@gmail.com: >>> From: Michael Kelley <mhklinux@outlook.com> >>> >>> A recent commit removing the use of screen_info introduced a logic >>> error. The error causes hvfb_getmem() to always return -ENOMEM >>> for Generation 2 VMs. As a result, the Hyper-V frame buffer >>> device fails to initialize. The error was introduced by removing >>> an "else if" clause, leaving Gen2 VMs to always take the -ENOMEM >>> error path. >>> >>> Fix the problem by removing the error path "else" clause. Gen 2 >>> VMs now always proceed through the MMIO memory allocation code, >>> but with "base" and "size" defaulting to 0. >> >> Indeed, that's how it was supposed to work. IDK how I didn't notice this >> bug. Thanks a lot for the fix. >> >>> >>> Fixes: 0aa0838c84da ("fbdev/hyperv_fb: Remove firmware framebufferswith aperture helpers") >>> Signed-off-by: Michael Kelley <mhklinux@outlook.com> >> >> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> > > Wei Liu and Helge Deller -- > > Should this fix go through the Hyper-V tree or the fbdev tree? I'm not > aware of a reason that it really matters, but it needs to be one or the > other, and sooner rather than later, because the Hyper-V driver is broken > starting in 6.8-rc1. I'm fine with either. If there is an upcoming hyper-v pull request, I'm fine if this is included there. If not, let me know and I can take it via fbdev. Helge > > Michael > >> >>> --- >>> drivers/video/fbdev/hyperv_fb.c | 2 -- >>> 1 file changed, 2 deletions(-) >>> >>> diff --git a/drivers/video/fbdev/hyperv_fb.c >> b/drivers/video/fbdev/hyperv_fb.c >>> index c26ee6fd73c9..8fdccf033b2d 100644 >>> --- a/drivers/video/fbdev/hyperv_fb.c >>> +++ b/drivers/video/fbdev/hyperv_fb.c >>> @@ -1010,8 +1010,6 @@ static int hvfb_getmem(struct hv_device *hdev, >> struct fb_info *info) >>> goto getmem_done; >>> } >>> pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n"); >>> - } else { >>> - goto err1; >>> } >>> >>> /* >> > >
On Fri, Feb 09, 2024 at 04:53:37PM +0100, Helge Deller wrote: > On 2/9/24 16:23, Michael Kelley wrote: > > From: Thomas Zimmermann <tzimmermann@suse.de> Sent: Thursday, February 1, 2024 12:17 AM [...] > > > > Wei Liu and Helge Deller -- > > > > Should this fix go through the Hyper-V tree or the fbdev tree? I'm not > > aware of a reason that it really matters, but it needs to be one or the > > other, and sooner rather than later, because the Hyper-V driver is broken > > starting in 6.8-rc1. > > I'm fine with either. > If there is an upcoming hyper-v pull request, I'm fine if this is included > there. If not, let me know and I can take it via fbdev. I've applied this to the hyperv-fixes tree. Thanks.
From: Wei Liu <wei.liu@kernel.org> Sent: Friday, March 1, 2024 1:26 AM > > On Fri, Feb 09, 2024 at 04:53:37PM +0100, Helge Deller wrote: > > On 2/9/24 16:23, Michael Kelley wrote: > > > From: Thomas Zimmermann <tzimmermann@suse.de> Sent: Thursday, February 1, 2024 12:17 AM > [...] > > > > > > Wei Liu and Helge Deller -- > > > > > > Should this fix go through the Hyper-V tree or the fbdev tree? I'm not > > > aware of a reason that it really matters, but it needs to be one or the > > > other, and sooner rather than later, because the Hyper-V driver is broken > > > starting in 6.8-rc1. > > > > I'm fine with either. > > If there is an upcoming hyper-v pull request, I'm fine if this is included > > there. If not, let me know and I can take it via fbdev. > > I've applied this to the hyperv-fixes tree. Thanks. Thanks, Wei, for picking up this patch as well as several others of mine. Michael
diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c index c26ee6fd73c9..8fdccf033b2d 100644 --- a/drivers/video/fbdev/hyperv_fb.c +++ b/drivers/video/fbdev/hyperv_fb.c @@ -1010,8 +1010,6 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info) goto getmem_done; } pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n"); - } else { - goto err1; } /*