| Message ID | 20210711210140.26994-1-chris.packham@alliedtelesis.co.nz |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: mpc: Poll for MCF | expand |
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index 6d5014ebaab5..db2e4ae24ee4 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -635,8 +635,7 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id) status = readb(i2c->base + MPC_I2C_SR); if (status & CSR_MIF) { - /* Read again to allow register to stabilise */ - status = readb(i2c->base + MPC_I2C_SR); + readb_poll_timeout(i2c->base + MPC_I2C_SR, status, !(status & CSR_MCF), 0, 100); writeb(0, i2c->base + MPC_I2C_SR); mpc_i2c_do_intr(i2c, status); return IRQ_HANDLED;
During some transfers the bus can still be busy when an interrupt is received. Commit 763778cd7926 ("i2c: mpc: Restore reread of I2C status register") attempted to address this by re-reading MPC_I2C_SR once but that just made it less likely to happen without actually preventing it. Instead of a single re-read poll with a timeout so that the bus is given enough time to settle but a genuine stuck SCL is still noticed. Fixes: 1538d82f4647 ("i2c: mpc: Interrupt driven transfer") Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> --- drivers/i2c/busses/i2c-mpc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)