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V4L/DVB (4784): [saa7146_i2c] short_delay mode fixed for fast machines

TT DVB-C 2300 runs at 137 kHz I2C speed. short_delay mode did not work
reliably on fast machines with that speed. Increased max loop count from
20 to 50. Moved dummy access out of the loop.

Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Oliver Endriss 18 年之前
父節點
當前提交
9bb6e2593a
共有 1 個文件被更改,包括 4 次插入6 次删除
  1. 4 6
      drivers/media/common/saa7146_i2c.c

+ 4 - 6
drivers/media/common/saa7146_i2c.c

@@ -217,11 +217,9 @@ static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_d
 		}
 		}
 		/* wait until we get a transfer done or error */
 		/* wait until we get a transfer done or error */
 		timeout = jiffies + HZ/100 + 1; /* 10ms */
 		timeout = jiffies + HZ/100 + 1; /* 10ms */
+		/* first read usually delivers bogus results... */
+		saa7146_i2c_status(dev);
 		while(1) {
 		while(1) {
-			/**
-			 *  first read usually delivers bogus results...
-			 */
-			saa7146_i2c_status(dev);
 			status = saa7146_i2c_status(dev);
 			status = saa7146_i2c_status(dev);
 			if ((status & 0x3) != 1)
 			if ((status & 0x3) != 1)
 				break;
 				break;
@@ -232,10 +230,10 @@ static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_d
 				DEB_I2C(("saa7146_i2c_writeout: timed out waiting for end of xfer\n"));
 				DEB_I2C(("saa7146_i2c_writeout: timed out waiting for end of xfer\n"));
 				return -EIO;
 				return -EIO;
 			}
 			}
-			if ((++trial < 20) && short_delay)
+			if (++trial < 50 && short_delay)
 				udelay(10);
 				udelay(10);
 			else
 			else
-			msleep(1);
+				msleep(1);
 		}
 		}
 	}
 	}