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| author |   Chris Packham <chris.packham@alliedtelesis.co.nz> | 2021-12-07 17:21:44 +1300 |
|---|---|---|
| committer |   Wolfram Sang <wsa@kernel.org> | 2021-12-10 22:27:30 +0100 |
| commit | a74c313aca266fab0d1d1a72becbb8b7b5286b6e (patch) | |
| tree | 3c41f5089c73b7d05337d8d5685aef0137c66024 /drivers/i2c/busses/i2c-mpc.c | |
| parent | i2c: virtio: fix completion handling (diff) | |
| download | linux-dev-a74c313aca266fab0d1d1a72becbb8b7b5286b6e.tar.xz linux-dev-a74c313aca266fab0d1d1a72becbb8b7b5286b6e.zip | |
i2c: mpc: Use atomic read and fix break condition
Maxime points out that the polling code in mpc_i2c_isr should use the
_atomic API because it is called in an irq context and that the
behaviour of the MCF bit is that it is 1 when the byte transfer is
complete. All of this means the original code was effectively a
udelay(100).
Fix this by using readb_poll_timeout_atomic() and removing the negation
of the break condition.
Fixes: 4a8ac5e45cda ("i2c: mpc: Poll for MCF")
Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Tested-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | drivers/i2c/busses/i2c-mpc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index a6ea1eb1394e..53b8da6dbb23 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -636,7 +636,7 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id) status = readb(i2c->base + MPC_I2C_SR); if (status & CSR_MIF) { /* Wait up to 100us for transfer to properly complete */ - readb_poll_timeout(i2c->base + MPC_I2C_SR, status, !(status & CSR_MCF), 0, 100); + readb_poll_timeout_atomic(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; |