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i2c-omap: Double clear of ARDY status in IRQ handler

This errata occurs when the ARDY interrupt generation is enabled.
At the begining of every new transaction the ARDY interrupt is cleared.

On continuous i2c transactions where after clearing the ARDY bit from
I2C_STAT register (clearing the interrupt), the IRQ line is reasserted and the
I2C_STAT[ARDY] bit set again on 1. In fact, the ARDY status bit is not cleared
at the write access to I2C_STAT[ARDY] and only the IRQ line is deasserted and
then reasserted. This is not captured in the usual errata documents.

The workaround is to have a double clear of ARDY status in irq handler.

Signed-off-by: Richard woodruff <r-woodruff2@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Richard woodruff 15 năm trước cách đây
mục cha
commit
cb527ede1b
1 tập tin đã thay đổi với 5 bổ sung1 xóa
  1. 5 1
      drivers/i2c/busses/i2c-omap.c

+ 5 - 1
drivers/i2c/busses/i2c-omap.c

@@ -847,11 +847,15 @@ complete:
 			dev_err(dev->dev, "Arbitration lost\n");
 			err |= OMAP_I2C_STAT_AL;
 		}
+		/* 
+		 * ProDB0017052: Clear ARDY bit twice
+		 */ 
 		if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
 					OMAP_I2C_STAT_AL)) {
 			omap_i2c_ack_stat(dev, stat &
 				(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
-				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
+				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR |
+				OMAP_I2C_STAT_ARDY));
 			omap_i2c_complete_cmd(dev, err);
 			return IRQ_HANDLED;
 		}