| Message ID | 20230426194956.689756-1-reidt@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] i2c: omap: Fix standard mode false ACK readings | expand |
On 4/27/2023 1:19 AM, Reid Tonking wrote: > 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: 3b2f8f82dad7 ("i2c: omap: switch to threaded IRQ support") > Signed-off-by: Reid Tonking <reidt@ti.com> Acked-by: Vignesh Raghavendra <vigneshr@ti.com> Regards Vignesh
* Raghavendra, Vignesh <vigneshr@ti.com> [230427 13:18]: > On 4/27/2023 1:19 AM, Reid Tonking wrote: > > 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. So is it safe to leave NACK interrupt unhandled until we get the next interrupt, does the ARDY always trigger after hitting this? Regards, Tony
On 10:43-20230428, Tony Lindgren wrote: > * Raghavendra, Vignesh <vigneshr@ti.com> [230427 13:18]: > > On 4/27/2023 1:19 AM, Reid Tonking wrote: > > > 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. > > So is it safe to leave NACK interrupt unhandled until we get the next > interrupt, does the ARDY always trigger after hitting this? > > Regards, > > Tony Yep, the ARDY always gets set after a new command when register access is ready so there's no need for NACK interrupt to control this. -Reid
On Wed, Apr 26, 2023 at 02:49:56PM -0500, Reid Tonking wrote: > 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: 3b2f8f82dad7 ("i2c: omap: switch to threaded IRQ support") > Signed-off-by: Reid Tonking <reidt@ti.com> Applied to for-current, thanks!
* Reid Tonking <reidt@ti.com> [230428 18:30]: > On 10:43-20230428, Tony Lindgren wrote: > > * Raghavendra, Vignesh <vigneshr@ti.com> [230427 13:18]: > > > On 4/27/2023 1:19 AM, Reid Tonking wrote: > > > > 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. > > > > So is it safe to leave NACK interrupt unhandled until we get the next > > interrupt, does the ARDY always trigger after hitting this? > > > > Regards, > > > > Tony > > Yep, the ARDY always gets set after a new command when register access is ready so there's no need for NACK interrupt to control this. OK thanks, looks good to me: Reviewed-by: Tony Lindgren <tony@atomide.com>
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 2b4e2be51318..4199f57a6bf2 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -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;
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: 3b2f8f82dad7 ("i2c: omap: switch to threaded IRQ support") Signed-off-by: Reid Tonking <reidt@ti.com> --- drivers/i2c/busses/i2c-omap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)