linux-fbdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH 0/5] video: fbdev: ssd1307fb: Optimizations and improvements
@ 2021-05-18  8:28 Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 1/5] video: fbdev: ssd1307fb: Propagate errors via ssd1307fb_update_display() Geert Uytterhoeven
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2021-05-18  8:28 UTC (permalink / raw)
  To: Maxime Ripard, David Airlie, Daniel Vetter
  Cc: linux-fbdev, dri-devel, linux-kernel, Geert Uytterhoeven

	Hi all,

This patch series optimizes console operations on ssd1307fb, after the
customary fixes and cleanups.

Currently, each screen update triggers an I2C transfer of all screen
data, up to 1 KiB of data for a 128x64 display, which takes at least 20
ms in Fast mode.  While many displays are smaller, and thus require less
data to be transferred, 20 ms is still an optimistic value, as the
actual data transfer may be much slower, especially on bitbanged I2C
drivers.  After this series, the amount of data transfer is reduced, as
fillrect, copyarea, and imageblit only update the rectangle that
changed.

This has been tested on an Adafruit FeatherWing OLED with an SSD1306
controller and a 128x32 OLED, connected to an OrangeCrab ECP5 FPGA board
running a 64 MHz VexRiscv RISC-V softcore, where it reduced the CPU
usage for blinking the cursor from more than 70% to ca. 10%.

Thanks for your comments!

Geert Uytterhoeven (5):
  video: fbdev: ssd1307fb: Propagate errors via
    ssd1307fb_update_display()
  video: fbdev: ssd1307fb: Simplify ssd1307fb_update_display()
  video: fbdev: ssd1307fb: Extract ssd1307fb_set_address_range()
  video: fbdev: ssd1307fb: Optimize screen updates
  video: fbdev: ssd1307fb: Cache address ranges

 drivers/video/fbdev/ssd1307fb.c | 143 +++++++++++++++++++++-----------
 1 file changed, 96 insertions(+), 47 deletions(-)

-- 
2.25.1

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 1/5] video: fbdev: ssd1307fb: Propagate errors via ssd1307fb_update_display()
  2021-05-18  8:28 [PATCH 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Geert Uytterhoeven
@ 2021-05-18  8:28 ` Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 2/5] video: fbdev: ssd1307fb: Simplify ssd1307fb_update_display() Geert Uytterhoeven
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2021-05-18  8:28 UTC (permalink / raw)
  To: Maxime Ripard, David Airlie, Daniel Vetter
  Cc: linux-fbdev, dri-devel, linux-kernel, Geert Uytterhoeven

Make ssd1307fb_update_display() return an error code, so callers that
can handle failures can propagate it.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 drivers/video/fbdev/ssd1307fb.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index eda448b7a0c9d8ce..e6b6263e3bef847f 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -152,17 +152,17 @@ static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
 	return ret;
 }
 
-static void ssd1307fb_update_display(struct ssd1307fb_par *par)
+static int ssd1307fb_update_display(struct ssd1307fb_par *par)
 {
 	struct ssd1307fb_array *array;
 	u8 *vmem = par->info->screen_buffer;
 	unsigned int line_length = par->info->fix.line_length;
 	unsigned int pages = DIV_ROUND_UP(par->height, 8);
-	int i, j, k;
+	int ret, i, j, k;
 
 	array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA);
 	if (!array)
-		return;
+		return -ENOMEM;
 
 	/*
 	 * The screen is divided in pages, each having a height of 8
@@ -210,8 +210,9 @@ static void ssd1307fb_update_display(struct ssd1307fb_par *par)
 		}
 	}
 
-	ssd1307fb_write_array(par->client, array, par->width * pages);
+	ret = ssd1307fb_write_array(par->client, array, par->width * pages);
 	kfree(array);
+	return ret;
 }
 
 
@@ -222,6 +223,7 @@ static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
 	unsigned long total_size;
 	unsigned long p = *ppos;
 	void *dst;
+	int ret;
 
 	total_size = info->fix.smem_len;
 
@@ -239,7 +241,9 @@ static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
 	if (copy_from_user(dst, buf, count))
 		return -EFAULT;
 
-	ssd1307fb_update_display(par);
+	ret = ssd1307fb_update_display(par);
+	if (ret < 0)
+		return ret;
 
 	*ppos += count;
 
@@ -483,7 +487,9 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 		return ret;
 
 	/* Clear the screen */
-	ssd1307fb_update_display(par);
+	ret = ssd1307fb_update_display(par);
+	if (ret < 0)
+		return ret;
 
 	/* Turn on the display */
 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
-- 
2.25.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 2/5] video: fbdev: ssd1307fb: Simplify ssd1307fb_update_display()
  2021-05-18  8:28 [PATCH 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 1/5] video: fbdev: ssd1307fb: Propagate errors via ssd1307fb_update_display() Geert Uytterhoeven
@ 2021-05-18  8:28 ` Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 3/5] video: fbdev: ssd1307fb: Extract ssd1307fb_set_address_range() Geert Uytterhoeven
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2021-05-18  8:28 UTC (permalink / raw)
  To: Maxime Ripard, David Airlie, Daniel Vetter
  Cc: linux-fbdev, dri-devel, linux-kernel, Geert Uytterhoeven

Simplify the nested loops to handle conversion from linear frame buffer
to ssd1307 page layout:
  1. Move last page handling one level up, as the value of "m" is the
     same inside a page,
  2. array->data[] is filled linearly, so there is no need to
     recalculate array_idx over and over again; a simple increment is
     sufficient.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 drivers/video/fbdev/ssd1307fb.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index e6b6263e3bef847f..6d7bd025bca1a175 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -158,6 +158,7 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par)
 	u8 *vmem = par->info->screen_buffer;
 	unsigned int line_length = par->info->fix.line_length;
 	unsigned int pages = DIV_ROUND_UP(par->height, 8);
+	u32 array_idx = 0;
 	int ret, i, j, k;
 
 	array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA);
@@ -194,19 +195,21 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par)
 	 */
 
 	for (i = 0; i < pages; i++) {
+		int m = 8;
+
+		/* Last page may be partial */
+		if (i + 1 == pages && par->height % 8)
+			m = par->height % 8;
 		for (j = 0; j < par->width; j++) {
-			int m = 8;
-			u32 array_idx = i * par->width + j;
-			array->data[array_idx] = 0;
-			/* Last page may be partial */
-			if (i + 1 == pages && par->height % 8)
-				m = par->height % 8;
+			u8 data = 0;
+
 			for (k = 0; k < m; k++) {
 				u8 byte = vmem[(8 * i + k) * line_length +
 					       j / 8];
 				u8 bit = (byte >> (j % 8)) & 1;
-				array->data[array_idx] |= bit << k;
+				data |= bit << k;
 			}
+			array->data[array_idx++] = data;
 		}
 	}
 
-- 
2.25.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 3/5] video: fbdev: ssd1307fb: Extract ssd1307fb_set_address_range()
  2021-05-18  8:28 [PATCH 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 1/5] video: fbdev: ssd1307fb: Propagate errors via ssd1307fb_update_display() Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 2/5] video: fbdev: ssd1307fb: Simplify ssd1307fb_update_display() Geert Uytterhoeven
@ 2021-05-18  8:28 ` Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 4/5] video: fbdev: ssd1307fb: Optimize screen updates Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 5/5] video: fbdev: ssd1307fb: Cache address ranges Geert Uytterhoeven
  4 siblings, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2021-05-18  8:28 UTC (permalink / raw)
  To: Maxime Ripard, David Airlie, Daniel Vetter
  Cc: linux-fbdev, dri-devel, linux-kernel, Geert Uytterhoeven

Extract the code to set the column and page ranges into a helper
function.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 drivers/video/fbdev/ssd1307fb.c | 61 +++++++++++++++++++--------------
 1 file changed, 36 insertions(+), 25 deletions(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index 6d7bd025bca1a175..cfa27ea0feab4f01 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -152,6 +152,38 @@ static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
 	return ret;
 }
 
+static int ssd1307fb_set_address_range(struct ssd1307fb_par *par, u8 col_start,
+				       u8 cols, u8 page_start, u8 pages)
+{
+	u8 col_end = col_start + cols - 1;
+	u8 page_end = page_start + pages - 1;
+	int ret;
+
+	/* Set column range */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, col_start);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, col_end);
+	if (ret < 0)
+		return ret;
+
+	/* Set page range */
+	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
+	if (ret < 0)
+		return ret;
+
+	ret = ssd1307fb_write_cmd(par->client, page_start);
+	if (ret < 0)
+		return ret;
+
+	return ssd1307fb_write_cmd(par->client, page_end);
+}
+
 static int ssd1307fb_update_display(struct ssd1307fb_par *par)
 {
 	struct ssd1307fb_array *array;
@@ -461,31 +493,10 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 	if (ret < 0)
 		return ret;
 
-	/* Set column range */
-	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
-	if (ret < 0)
-		return ret;
-
-	ret = ssd1307fb_write_cmd(par->client, par->col_offset);
-	if (ret < 0)
-		return ret;
-
-	ret = ssd1307fb_write_cmd(par->client, par->col_offset + par->width - 1);
-	if (ret < 0)
-		return ret;
-
-	/* Set page range */
-	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
-	if (ret < 0)
-		return ret;
-
-	ret = ssd1307fb_write_cmd(par->client, par->page_offset);
-	if (ret < 0)
-		return ret;
-
-	ret = ssd1307fb_write_cmd(par->client,
-				  par->page_offset +
-				  DIV_ROUND_UP(par->height, 8) - 1);
+	/* Set column and page range */
+	ret = ssd1307fb_set_address_range(par, par->col_offset, par->width,
+					  par->page_offset,
+					  DIV_ROUND_UP(par->height, 8));
 	if (ret < 0)
 		return ret;
 
-- 
2.25.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 4/5] video: fbdev: ssd1307fb: Optimize screen updates
  2021-05-18  8:28 [PATCH 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Geert Uytterhoeven
                   ` (2 preceding siblings ...)
  2021-05-18  8:28 ` [PATCH 3/5] video: fbdev: ssd1307fb: Extract ssd1307fb_set_address_range() Geert Uytterhoeven
@ 2021-05-18  8:28 ` Geert Uytterhoeven
  2021-05-18  8:28 ` [PATCH 5/5] video: fbdev: ssd1307fb: Cache address ranges Geert Uytterhoeven
  4 siblings, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2021-05-18  8:28 UTC (permalink / raw)
  To: Maxime Ripard, David Airlie, Daniel Vetter
  Cc: linux-fbdev, dri-devel, linux-kernel, Geert Uytterhoeven

Currently, each screen update triggers an I2C transfer of all screen
data, up to 1 KiB of data for a 128x64 display, which takes at least 20
ms in Fast mode.

Reduce the amount of transferred data by only updating the rectangle
that changed.  Remove the call to ssd1307fb_set_address_range() during
initialization, as ssd1307fb_update_rect() now takes care of that.

Note that for now the optimized operation is only used for fillrect,
copyarea, and imageblit, which are used by fbcon.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 drivers/video/fbdev/ssd1307fb.c | 43 ++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 17 deletions(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index cfa27ea0feab4f01..8e3d4be74723b9bf 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -184,16 +184,18 @@ static int ssd1307fb_set_address_range(struct ssd1307fb_par *par, u8 col_start,
 	return ssd1307fb_write_cmd(par->client, page_end);
 }
 
-static int ssd1307fb_update_display(struct ssd1307fb_par *par)
+static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,
+				 unsigned int y, unsigned int width,
+				 unsigned int height)
 {
 	struct ssd1307fb_array *array;
 	u8 *vmem = par->info->screen_buffer;
 	unsigned int line_length = par->info->fix.line_length;
-	unsigned int pages = DIV_ROUND_UP(par->height, 8);
+	unsigned int pages = DIV_ROUND_UP(height + y % 8, 8);
 	u32 array_idx = 0;
 	int ret, i, j, k;
 
-	array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA);
+	array = ssd1307fb_alloc_array(width * pages, SSD1307FB_DATA);
 	if (!array)
 		return -ENOMEM;
 
@@ -226,13 +228,18 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par)
 	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
 	 */
 
-	for (i = 0; i < pages; i++) {
+	ret = ssd1307fb_set_address_range(par, par->col_offset + x, width,
+					  par->page_offset + y / 8, pages);
+	if (ret < 0)
+		goto out_free;
+
+	for (i = y / 8; i < y / 8 + pages; i++) {
 		int m = 8;
 
 		/* Last page may be partial */
-		if (i + 1 == pages && par->height % 8)
+		if (8 * (i + 1) > par->height)
 			m = par->height % 8;
-		for (j = 0; j < par->width; j++) {
+		for (j = x; j < x + width; j++) {
 			u8 data = 0;
 
 			for (k = 0; k < m; k++) {
@@ -245,11 +252,17 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par)
 		}
 	}
 
-	ret = ssd1307fb_write_array(par->client, array, par->width * pages);
+	ret = ssd1307fb_write_array(par->client, array, width * pages);
+
+out_free:
 	kfree(array);
 	return ret;
 }
 
+static int ssd1307fb_update_display(struct ssd1307fb_par *par)
+{
+	return ssd1307fb_update_rect(par, 0, 0, par->width, par->height);
+}
 
 static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
 		size_t count, loff_t *ppos)
@@ -299,21 +312,24 @@ static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *r
 {
 	struct ssd1307fb_par *par = info->par;
 	sys_fillrect(info, rect);
-	ssd1307fb_update_display(par);
+	ssd1307fb_update_rect(par, rect->dx, rect->dy, rect->width,
+			      rect->height);
 }
 
 static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
 {
 	struct ssd1307fb_par *par = info->par;
 	sys_copyarea(info, area);
-	ssd1307fb_update_display(par);
+	ssd1307fb_update_rect(par, area->dx, area->dy, area->width,
+			      area->height);
 }
 
 static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image)
 {
 	struct ssd1307fb_par *par = info->par;
 	sys_imageblit(info, image);
-	ssd1307fb_update_display(par);
+	ssd1307fb_update_rect(par, image->dx, image->dy, image->width,
+			      image->height);
 }
 
 static const struct fb_ops ssd1307fb_ops = {
@@ -493,13 +509,6 @@ static int ssd1307fb_init(struct ssd1307fb_par *par)
 	if (ret < 0)
 		return ret;
 
-	/* Set column and page range */
-	ret = ssd1307fb_set_address_range(par, par->col_offset, par->width,
-					  par->page_offset,
-					  DIV_ROUND_UP(par->height, 8));
-	if (ret < 0)
-		return ret;
-
 	/* Clear the screen */
 	ret = ssd1307fb_update_display(par);
 	if (ret < 0)
-- 
2.25.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 5/5] video: fbdev: ssd1307fb: Cache address ranges
  2021-05-18  8:28 [PATCH 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Geert Uytterhoeven
                   ` (3 preceding siblings ...)
  2021-05-18  8:28 ` [PATCH 4/5] video: fbdev: ssd1307fb: Optimize screen updates Geert Uytterhoeven
@ 2021-05-18  8:28 ` Geert Uytterhoeven
  4 siblings, 0 replies; 6+ messages in thread
From: Geert Uytterhoeven @ 2021-05-18  8:28 UTC (permalink / raw)
  To: Maxime Ripard, David Airlie, Daniel Vetter
  Cc: linux-fbdev, dri-devel, linux-kernel, Geert Uytterhoeven

Cache the column and page ranges, to avoid doing unneeded I2C transfers
when the values haven't changed.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
 drivers/video/fbdev/ssd1307fb.c | 52 +++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 16 deletions(-)

diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
index 8e3d4be74723b9bf..23b43ce479898813 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -82,6 +82,11 @@ struct ssd1307fb_par {
 	struct regulator *vbat_reg;
 	u32 vcomh;
 	u32 width;
+	/* Cached address ranges */
+	u8 col_start;
+	u8 col_end;
+	u8 page_start;
+	u8 page_end;
 };
 
 struct ssd1307fb_array {
@@ -160,28 +165,43 @@ static int ssd1307fb_set_address_range(struct ssd1307fb_par *par, u8 col_start,
 	int ret;
 
 	/* Set column range */
-	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
-	if (ret < 0)
-		return ret;
+	if (col_start != par->col_start || col_end != par->col_end) {
+		ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
+		if (ret < 0)
+			return ret;
 
-	ret = ssd1307fb_write_cmd(par->client, col_start);
-	if (ret < 0)
-		return ret;
+		ret = ssd1307fb_write_cmd(par->client, col_start);
+		if (ret < 0)
+			return ret;
 
-	ret = ssd1307fb_write_cmd(par->client, col_end);
-	if (ret < 0)
-		return ret;
+		ret = ssd1307fb_write_cmd(par->client, col_end);
+		if (ret < 0)
+			return ret;
+
+		par->col_start = col_start;
+		par->col_end = col_end;
+	}
 
 	/* Set page range */
-	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
-	if (ret < 0)
-		return ret;
+	if (page_start != par->page_start || page_end != par->page_end) {
+		ret = ssd1307fb_write_cmd(par->client,
+					  SSD1307FB_SET_PAGE_RANGE);
+		if (ret < 0)
+			return ret;
 
-	ret = ssd1307fb_write_cmd(par->client, page_start);
-	if (ret < 0)
-		return ret;
+		ret = ssd1307fb_write_cmd(par->client, page_start);
+		if (ret < 0)
+			return ret;
+
+		ret = ssd1307fb_write_cmd(par->client, page_end);
+		if (ret < 0)
+			return ret;
 
-	return ssd1307fb_write_cmd(par->client, page_end);
+		par->page_start = page_start;
+		par->page_end = page_end;
+	}
+
+	return 0;
 }
 
 static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,
-- 
2.25.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-05-18  9:06 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-18  8:28 [PATCH 0/5] video: fbdev: ssd1307fb: Optimizations and improvements Geert Uytterhoeven
2021-05-18  8:28 ` [PATCH 1/5] video: fbdev: ssd1307fb: Propagate errors via ssd1307fb_update_display() Geert Uytterhoeven
2021-05-18  8:28 ` [PATCH 2/5] video: fbdev: ssd1307fb: Simplify ssd1307fb_update_display() Geert Uytterhoeven
2021-05-18  8:28 ` [PATCH 3/5] video: fbdev: ssd1307fb: Extract ssd1307fb_set_address_range() Geert Uytterhoeven
2021-05-18  8:28 ` [PATCH 4/5] video: fbdev: ssd1307fb: Optimize screen updates Geert Uytterhoeven
2021-05-18  8:28 ` [PATCH 5/5] video: fbdev: ssd1307fb: Cache address ranges Geert Uytterhoeven

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).