Patch "Revert "Staging: panel: usleep_range is preferred over udelay"" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    Revert "Staging: panel: usleep_range is preferred over udelay"

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     revert-staging-panel-usleep_range-is-preferred-over-udelay.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From b64a1cbef6df47c986ad622b5b2e4d3d1940070c Mon Sep 17 00:00:00 2001
From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Date: Sat, 23 Jan 2016 14:49:20 +0530
Subject: Revert "Staging: panel: usleep_range is preferred over udelay"

From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>

commit b64a1cbef6df47c986ad622b5b2e4d3d1940070c upstream.

This reverts commit ebd43516d3879f882a403836bba8bc5791f26a28.

We should not be sleeping inside spin_lock.

Fixes: ebd43516d387 ("Staging: panel: usleep_range is preferred over udelay")
Cc: Sirnam Swetha <theonly.ultimate@gmail.com>
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Reported-by: Huang, Ying <ying.huang@intel.com>
Tested-by: Huang, Ying <ying.huang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
index 79ac19246548..70b8f4fabfad 100644
--- a/drivers/staging/panel/panel.c
+++ b/drivers/staging/panel/panel.c
@@ -825,8 +825,7 @@ static void lcd_write_cmd_s(int cmd)
 	lcd_send_serial(0x1F);	/* R/W=W, RS=0 */
 	lcd_send_serial(cmd & 0x0F);
 	lcd_send_serial((cmd >> 4) & 0x0F);
-	/* the shortest command takes at least 40 us */
-	usleep_range(40, 100);
+	udelay(40);		/* the shortest command takes at least 40 us */
 	spin_unlock_irq(&pprt_lock);
 }
 
@@ -837,8 +836,7 @@ static void lcd_write_data_s(int data)
 	lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
 	lcd_send_serial(data & 0x0F);
 	lcd_send_serial((data >> 4) & 0x0F);
-	/* the shortest data takes at least 40 us */
-	usleep_range(40, 100);
+	udelay(40);		/* the shortest data takes at least 40 us */
 	spin_unlock_irq(&pprt_lock);
 }
 
@@ -848,20 +846,19 @@ static void lcd_write_cmd_p8(int cmd)
 	spin_lock_irq(&pprt_lock);
 	/* present the data to the data port */
 	w_dtr(pprt, cmd);
-	/* maintain the data during 20 us before the strobe */
-	usleep_range(20, 100);
+	udelay(20);	/* maintain the data during 20 us before the strobe */
 
 	bits.e = BIT_SET;
 	bits.rs = BIT_CLR;
 	bits.rw = BIT_CLR;
 	set_ctrl_bits();
 
-	usleep_range(40, 100);	/* maintain the strobe during 40 us */
+	udelay(40);	/* maintain the strobe during 40 us */
 
 	bits.e = BIT_CLR;
 	set_ctrl_bits();
 
-	usleep_range(120, 500);	/* the shortest command takes at least 120 us */
+	udelay(120);	/* the shortest command takes at least 120 us */
 	spin_unlock_irq(&pprt_lock);
 }
 
@@ -871,20 +868,19 @@ static void lcd_write_data_p8(int data)
 	spin_lock_irq(&pprt_lock);
 	/* present the data to the data port */
 	w_dtr(pprt, data);
-	/* maintain the data during 20 us before the strobe */
-	usleep_range(20, 100);
+	udelay(20);	/* maintain the data during 20 us before the strobe */
 
 	bits.e = BIT_SET;
 	bits.rs = BIT_SET;
 	bits.rw = BIT_CLR;
 	set_ctrl_bits();
 
-	usleep_range(40, 100);	/* maintain the strobe during 40 us */
+	udelay(40);	/* maintain the strobe during 40 us */
 
 	bits.e = BIT_CLR;
 	set_ctrl_bits();
 
-	usleep_range(45, 100);	/* the shortest data takes at least 45 us */
+	udelay(45);	/* the shortest data takes at least 45 us */
 	spin_unlock_irq(&pprt_lock);
 }
 
@@ -894,7 +890,7 @@ static void lcd_write_cmd_tilcd(int cmd)
 	spin_lock_irq(&pprt_lock);
 	/* present the data to the control port */
 	w_ctr(pprt, cmd);
-	usleep_range(60, 120);
+	udelay(60);
 	spin_unlock_irq(&pprt_lock);
 }
 
@@ -904,7 +900,7 @@ static void lcd_write_data_tilcd(int data)
 	spin_lock_irq(&pprt_lock);
 	/* present the data to the data port */
 	w_dtr(pprt, data);
-	usleep_range(60, 120);
+	udelay(60);
 	spin_unlock_irq(&pprt_lock);
 }
 
@@ -947,7 +943,7 @@ static void lcd_clear_fast_s(void)
 		lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
 		lcd_send_serial(' ' & 0x0F);
 		lcd_send_serial((' ' >> 4) & 0x0F);
-		usleep_range(40, 100);	/* the shortest data takes at least 40 us */
+		udelay(40);	/* the shortest data takes at least 40 us */
 	}
 	spin_unlock_irq(&pprt_lock);
 
@@ -971,7 +967,7 @@ static void lcd_clear_fast_p8(void)
 		w_dtr(pprt, ' ');
 
 		/* maintain the data during 20 us before the strobe */
-		usleep_range(20, 100);
+		udelay(20);
 
 		bits.e = BIT_SET;
 		bits.rs = BIT_SET;
@@ -979,13 +975,13 @@ static void lcd_clear_fast_p8(void)
 		set_ctrl_bits();
 
 		/* maintain the strobe during 40 us */
-		usleep_range(40, 100);
+		udelay(40);
 
 		bits.e = BIT_CLR;
 		set_ctrl_bits();
 
 		/* the shortest data takes at least 45 us */
-		usleep_range(45, 100);
+		udelay(45);
 	}
 	spin_unlock_irq(&pprt_lock);
 
@@ -1007,7 +1003,7 @@ static void lcd_clear_fast_tilcd(void)
 	for (pos = 0; pos < lcd.height * lcd.hwidth; pos++) {
 		/* present the data to the data port */
 		w_dtr(pprt, ' ');
-		usleep_range(60, 120);
+		udelay(60);
 	}
 
 	spin_unlock_irq(&pprt_lock);


Patches currently in stable-queue which might be from sudipm.mukherjee@gmail.com are

queue-4.4/revert-staging-panel-usleep_range-is-preferred-over-udelay.patch