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* [PATCH] drm/tegra: dpaux: Fix transfers larger than 4 bytes
@ 2015-07-20  6:49 Thierry Reding
  2015-07-20  7:39 ` Steev Klimaszewski
  0 siblings, 1 reply; 3+ messages in thread
From: Thierry Reding @ 2015-07-20  6:49 UTC (permalink / raw)
  To: Thierry Reding
  Cc: dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW,
	linux-tegra-u79uwXL29TY76Z2rM5mHXA, Steev Klimaszewski

From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>

The DPAUX read/write FIFO registers aren't sequential in the register
space, causing transfers larger than 4 bytes to cause accesses to non-
existing FIFO registers.

Fixes: 6b6b604215c6 ("drm/tegra: Add eDP support")
Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
---
 drivers/gpu/drm/tegra/dpaux.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index d6b55e3e3716..a43a836e6f88 100644
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -72,34 +72,32 @@ static inline void tegra_dpaux_writel(struct tegra_dpaux *dpaux,
 static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8 *buffer,
 				   size_t size)
 {
-	unsigned long offset = DPAUX_DP_AUXDATA_WRITE(0);
 	size_t i, j;
 
-	for (i = 0; i < size; i += 4) {
-		size_t num = min_t(size_t, size - i, 4);
+	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
+		size_t num = min_t(size_t, size - i * 4, 4);
 		unsigned long value = 0;
 
 		for (j = 0; j < num; j++)
-			value |= buffer[i + j] << (j * 8);
+			value |= buffer[i * 4 + j] << (j * 8);
 
-		tegra_dpaux_writel(dpaux, value, offset++);
+		tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXDATA_WRITE(i));
 	}
 }
 
 static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
 				  size_t size)
 {
-	unsigned long offset = DPAUX_DP_AUXDATA_READ(0);
 	size_t i, j;
 
-	for (i = 0; i < size; i += 4) {
-		size_t num = min_t(size_t, size - i, 4);
+	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
+		size_t num = min_t(size_t, size - i * 4, 4);
 		unsigned long value;
 
-		value = tegra_dpaux_readl(dpaux, offset++);
+		value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));
 
 		for (j = 0; j < num; j++)
-			buffer[i + j] = value >> (j * 8);
+			buffer[i * 4 + j] = value >> (j * 8);
 	}
 }
 
-- 
2.4.5

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/tegra: dpaux: Fix transfers larger than 4 bytes
  2015-07-20  6:49 [PATCH] drm/tegra: dpaux: Fix transfers larger than 4 bytes Thierry Reding
@ 2015-07-20  7:39 ` Steev Klimaszewski
       [not found]   ` <CAOvMTZiuq=qesVD9PYuePz2zAKqh_m-1FbBZwBa6S4CLHv7mvw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
  0 siblings, 1 reply; 3+ messages in thread
From: Steev Klimaszewski @ 2015-07-20  7:39 UTC (permalink / raw)
  To: Thierry Reding; +Cc: linux-tegra, dri-devel


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On Mon, Jul 20, 2015 at 1:49 AM, Thierry Reding <thierry.reding@gmail.com>
wrote:

> From: Thierry Reding <treding@nvidia.com>
>
> The DPAUX read/write FIFO registers aren't sequential in the register
> space, causing transfers larger than 4 bytes to cause accesses to non-
> existing FIFO registers.
>
> Fixes: 6b6b604215c6 ("drm/tegra: Add eDP support")
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/gpu/drm/tegra/dpaux.c | 18 ++++++++----------
>  1 file changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
> index d6b55e3e3716..a43a836e6f88 100644
> --- a/drivers/gpu/drm/tegra/dpaux.c
> +++ b/drivers/gpu/drm/tegra/dpaux.c
> @@ -72,34 +72,32 @@ static inline void tegra_dpaux_writel(struct
> tegra_dpaux *dpaux,
>  static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8
> *buffer,
>                                    size_t size)
>  {
> -       unsigned long offset = DPAUX_DP_AUXDATA_WRITE(0);
>         size_t i, j;
>
> -       for (i = 0; i < size; i += 4) {
> -               size_t num = min_t(size_t, size - i, 4);
> +       for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
> +               size_t num = min_t(size_t, size - i * 4, 4);
>                 unsigned long value = 0;
>
>                 for (j = 0; j < num; j++)
> -                       value |= buffer[i + j] << (j * 8);
> +                       value |= buffer[i * 4 + j] << (j * 8);
>
> -               tegra_dpaux_writel(dpaux, value, offset++);
> +               tegra_dpaux_writel(dpaux, value,
> DPAUX_DP_AUXDATA_WRITE(i));
>         }
>  }
>
>  static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
>                                   size_t size)
>  {
> -       unsigned long offset = DPAUX_DP_AUXDATA_READ(0);
>         size_t i, j;
>
> -       for (i = 0; i < size; i += 4) {
> -               size_t num = min_t(size_t, size - i, 4);
> +       for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
> +               size_t num = min_t(size_t, size - i * 4, 4);
>                 unsigned long value;
>
> -               value = tegra_dpaux_readl(dpaux, offset++);
> +               value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));
>
>                 for (j = 0; j < num; j++)
> -                       buffer[i + j] = value >> (j * 8);
> +                       buffer[i * 4 + j] = value >> (j * 8);
>         }
>  }
>
> --
> 2.4.5
>
>

This fixes the issue that I reported earlier, so feel free to add my

Tested-by: Steev Klimaszewski <steev@gentoo.org>

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^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] drm/tegra: dpaux: Fix transfers larger than 4 bytes
       [not found]   ` <CAOvMTZiuq=qesVD9PYuePz2zAKqh_m-1FbBZwBa6S4CLHv7mvw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2015-07-20  9:35     ` Thierry Reding
  0 siblings, 0 replies; 3+ messages in thread
From: Thierry Reding @ 2015-07-20  9:35 UTC (permalink / raw)
  To: Steev Klimaszewski
  Cc: dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW,
	linux-tegra-u79uwXL29TY76Z2rM5mHXA

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On Mon, Jul 20, 2015 at 02:39:36AM -0500, Steev Klimaszewski wrote:
> On Mon, Jul 20, 2015 at 1:49 AM, Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> wrote:
> 
> > From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> >
> > The DPAUX read/write FIFO registers aren't sequential in the register
> > space, causing transfers larger than 4 bytes to cause accesses to non-
> > existing FIFO registers.
> >
> > Fixes: 6b6b604215c6 ("drm/tegra: Add eDP support")
> > Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
> > ---
> >  drivers/gpu/drm/tegra/dpaux.c | 18 ++++++++----------
> >  1 file changed, 8 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
> > index d6b55e3e3716..a43a836e6f88 100644
> > --- a/drivers/gpu/drm/tegra/dpaux.c
> > +++ b/drivers/gpu/drm/tegra/dpaux.c
> > @@ -72,34 +72,32 @@ static inline void tegra_dpaux_writel(struct
> > tegra_dpaux *dpaux,
> >  static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8
> > *buffer,
> >                                    size_t size)
> >  {
> > -       unsigned long offset = DPAUX_DP_AUXDATA_WRITE(0);
> >         size_t i, j;
> >
> > -       for (i = 0; i < size; i += 4) {
> > -               size_t num = min_t(size_t, size - i, 4);
> > +       for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
> > +               size_t num = min_t(size_t, size - i * 4, 4);
> >                 unsigned long value = 0;
> >
> >                 for (j = 0; j < num; j++)
> > -                       value |= buffer[i + j] << (j * 8);
> > +                       value |= buffer[i * 4 + j] << (j * 8);
> >
> > -               tegra_dpaux_writel(dpaux, value, offset++);
> > +               tegra_dpaux_writel(dpaux, value,
> > DPAUX_DP_AUXDATA_WRITE(i));
> >         }
> >  }
> >
> >  static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
> >                                   size_t size)
> >  {
> > -       unsigned long offset = DPAUX_DP_AUXDATA_READ(0);
> >         size_t i, j;
> >
> > -       for (i = 0; i < size; i += 4) {
> > -               size_t num = min_t(size_t, size - i, 4);
> > +       for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
> > +               size_t num = min_t(size_t, size - i * 4, 4);
> >                 unsigned long value;
> >
> > -               value = tegra_dpaux_readl(dpaux, offset++);
> > +               value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));
> >
> >                 for (j = 0; j < num; j++)
> > -                       buffer[i + j] = value >> (j * 8);
> > +                       buffer[i * 4 + j] = value >> (j * 8);
> >         }
> >  }
> >
> > --
> > 2.4.5
> >
> >
> 
> This fixes the issue that I reported earlier, so feel free to add my
> 
> Tested-by: Steev Klimaszewski <steev-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>

Great, thanks.

Thierry

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^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2015-07-20  9:35 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2015-07-20  6:49 [PATCH] drm/tegra: dpaux: Fix transfers larger than 4 bytes Thierry Reding
2015-07-20  7:39 ` Steev Klimaszewski
     [not found]   ` <CAOvMTZiuq=qesVD9PYuePz2zAKqh_m-1FbBZwBa6S4CLHv7mvw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-07-20  9:35     ` Thierry Reding

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