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* [PATCH v1] fbtft: fb_st7789v: added reset on init_display()
@ 2021-08-13  6:25 Oliver Graute
  2021-08-13  8:20 ` Greg KH
  0 siblings, 1 reply; 5+ messages in thread
From: Oliver Graute @ 2021-08-13  6:25 UTC (permalink / raw)
  To: gregkh
  Cc: oliver.graute, Oliver Graute, Carlis, dri-devel, linux-fbdev,
	linux-staging, linux-kernel

staging: fbtft: fb_st7789v: reset display before initialization

In rare cases the display is flipped or mirrored. This was observed more
often in a low temperature environment. A clean reset on init_display()
should help to get registers in a sane state.

Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
---
 drivers/staging/fbtft/fb_st7789v.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/fbtft/fb_st7789v.c b/drivers/staging/fbtft/fb_st7789v.c
index 3a280cc1892c..0a2dbed9ffc7 100644
--- a/drivers/staging/fbtft/fb_st7789v.c
+++ b/drivers/staging/fbtft/fb_st7789v.c
@@ -82,6 +82,8 @@ enum st7789v_command {
 {
 	int rc;

+	par->fbtftops.reset(par);
+
 	rc = init_tearing_effect_line(par);
 	if (rc)
 		return rc;
-- 
2.17.1


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v1] fbtft: fb_st7789v: added reset on init_display()
  2021-08-13  6:25 [PATCH v1] fbtft: fb_st7789v: added reset on init_display() Oliver Graute
@ 2021-08-13  8:20 ` Greg KH
  2021-08-13 12:54   ` Oliver Graute
  0 siblings, 1 reply; 5+ messages in thread
From: Greg KH @ 2021-08-13  8:20 UTC (permalink / raw)
  To: Oliver Graute
  Cc: oliver.graute, Carlis, dri-devel, linux-fbdev, linux-staging,
	linux-kernel

On Fri, Aug 13, 2021 at 08:25:10AM +0200, Oliver Graute wrote:
> staging: fbtft: fb_st7789v: reset display before initialization

What is this line here, and why is this not your subject line instead?

> 
> In rare cases the display is flipped or mirrored. This was observed more
> often in a low temperature environment. A clean reset on init_display()
> should help to get registers in a sane state.
> 
> Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>

What commit does this fix?

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v1] fbtft: fb_st7789v: added reset on init_display()
  2021-08-13  8:20 ` Greg KH
@ 2021-08-13 12:54   ` Oliver Graute
  2021-08-13 15:00     ` Greg KH
  0 siblings, 1 reply; 5+ messages in thread
From: Oliver Graute @ 2021-08-13 12:54 UTC (permalink / raw)
  To: Greg KH; +Cc: Carlis, dri-devel, linux-fbdev, linux-staging, linux-kernel

On 13/08/21, Greg KH wrote:
> On Fri, Aug 13, 2021 at 08:25:10AM +0200, Oliver Graute wrote:
> > staging: fbtft: fb_st7789v: reset display before initialization
> 
> What is this line here, and why is this not your subject line instead?

I'll put the line as subject instead.

> > In rare cases the display is flipped or mirrored. This was observed more
> > often in a low temperature environment. A clean reset on init_display()
> > should help to get registers in a sane state.
> > 
> > Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
> 
> What commit does this fix?

this is a fix for a rare behavior of the fb_st7789v display. Not a
bugfix for a specific commit.

Best regards,

Oliver

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v1] fbtft: fb_st7789v: added reset on init_display()
  2021-08-13 12:54   ` Oliver Graute
@ 2021-08-13 15:00     ` Greg KH
  2022-02-10  8:49       ` Oliver Graute
  0 siblings, 1 reply; 5+ messages in thread
From: Greg KH @ 2021-08-13 15:00 UTC (permalink / raw)
  To: Oliver Graute; +Cc: Carlis, dri-devel, linux-fbdev, linux-staging, linux-kernel

On Fri, Aug 13, 2021 at 02:54:30PM +0200, Oliver Graute wrote:
> On 13/08/21, Greg KH wrote:
> > On Fri, Aug 13, 2021 at 08:25:10AM +0200, Oliver Graute wrote:
> > > staging: fbtft: fb_st7789v: reset display before initialization
> > 
> > What is this line here, and why is this not your subject line instead?
> 
> I'll put the line as subject instead.
> 
> > > In rare cases the display is flipped or mirrored. This was observed more
> > > often in a low temperature environment. A clean reset on init_display()
> > > should help to get registers in a sane state.
> > > 
> > > Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
> > 
> > What commit does this fix?
> 
> this is a fix for a rare behavior of the fb_st7789v display. Not a
> bugfix for a specific commit.

So if it has always been broken, list the commit where the code was
added to the kernel, as this should be backported to the stable kernels,
right?

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v1] fbtft: fb_st7789v: added reset on init_display()
  2021-08-13 15:00     ` Greg KH
@ 2022-02-10  8:49       ` Oliver Graute
  0 siblings, 0 replies; 5+ messages in thread
From: Oliver Graute @ 2022-02-10  8:49 UTC (permalink / raw)
  To: Greg KH; +Cc: Carlis, dri-devel, linux-fbdev, linux-staging, linux-kernel

On 13/08/21, Greg KH wrote:
> On Fri, Aug 13, 2021 at 02:54:30PM +0200, Oliver Graute wrote:
> > On 13/08/21, Greg KH wrote:
> > > On Fri, Aug 13, 2021 at 08:25:10AM +0200, Oliver Graute wrote:
> > > > staging: fbtft: fb_st7789v: reset display before initialization
> > > 
> > > What is this line here, and why is this not your subject line instead?
> > 
> > I'll put the line as subject instead.
> > 
> > > > In rare cases the display is flipped or mirrored. This was observed more
> > > > often in a low temperature environment. A clean reset on init_display()
> > > > should help to get registers in a sane state.
> > > > 
> > > > Signed-off-by: Oliver Graute <oliver.graute@kococonnector.com>
> > > 
> > > What commit does this fix?
> > 
> > this is a fix for a rare behavior of the fb_st7789v display. Not a
> > bugfix for a specific commit.
> 
> So if it has always been broken, list the commit where the code was
> added to the kernel, as this should be backported to the stable kernels,
> right?

ok thx, will list the commit and add stable@vger.kernel.org to cc

thx,

Oliver

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2022-02-10  9:00 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-13  6:25 [PATCH v1] fbtft: fb_st7789v: added reset on init_display() Oliver Graute
2021-08-13  8:20 ` Greg KH
2021-08-13 12:54   ` Oliver Graute
2021-08-13 15:00     ` Greg KH
2022-02-10  8:49       ` Oliver Graute

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