Commit cb527ede authored by Richard woodruff's avatar Richard woodruff Committed by Ben Dooks

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: default avatarRichard woodruff <r-woodruff2@ti.com>
Signed-off-by: default avatarKeerthy <j-keerthy@ti.com>
Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
parent f72487e7
...@@ -847,11 +847,15 @@ omap_i2c_isr(int this_irq, void *dev_id) ...@@ -847,11 +847,15 @@ omap_i2c_isr(int this_irq, void *dev_id)
dev_err(dev->dev, "Arbitration lost\n"); dev_err(dev->dev, "Arbitration lost\n");
err |= OMAP_I2C_STAT_AL; err |= OMAP_I2C_STAT_AL;
} }
/*
* ProDB0017052: Clear ARDY bit twice
*/
if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
OMAP_I2C_STAT_AL)) { OMAP_I2C_STAT_AL)) {
omap_i2c_ack_stat(dev, stat & omap_i2c_ack_stat(dev, stat &
(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR | (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); omap_i2c_complete_cmd(dev, err);
return IRQ_HANDLED; return IRQ_HANDLED;
} }
......
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