i2c: omap: Fix standard mode false ACK readings

commit c770657bd2611b077ec1e7b1fe6aa92f249399bd upstream.

Using standard mode, rare false ACK responses were appearing with
i2cdetect tool. This was happening due to NACK interrupt triggering
ISR thread before register access interrupt was ready. Removing the
NACK interrupt's ability to trigger ISR thread lets register access
ready interrupt do this instead.

Cc: <stable@vger.kernel.org> # v3.7+
Fixes: 3b2f8f82da ("i2c: omap: switch to threaded IRQ support")
Signed-off-by: Reid Tonking <reidt@ti.com>
Acked-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Reid Tonking 2023-04-26 14:49:56 -05:00 committed by Greg Kroah-Hartman
parent 142a975738
commit 3c96dd239a

View File

@ -1058,7 +1058,7 @@ omap_i2c_isr(int irq, void *dev_id)
u16 stat;
stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG) & ~OMAP_I2C_STAT_NACK;
if (stat & mask)
ret = IRQ_WAKE_THREAD;