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Revert "i2c: tegra: Better handle case where CPU0 is busy for a long time" 

This reverts commit a900aeac25 because
regressions were showing up.

Suggested-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/dmaengine/20200319201140.17451-1-digetx@gmail.com/
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
alistair/sensors
Wolfram Sang 2020-04-27 10:52:22 +02:00
parent deb821ffe2
commit 8839e4605e
1 changed files with 12 additions and 15 deletions
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27
drivers/i2c/busses/i2c-tegra.c
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@ -996,13 +996,14 @@ tegra_i2c_poll_completion_timeout(struct tegra_i2c_dev *i2c_dev,
do {
u32 status = i2c_readl(i2c_dev, I2C_INT_STATUS);
if (status)
if (status) {
tegra_i2c_isr(i2c_dev->irq, i2c_dev);
if (completion_done(complete)) {
s64 delta = ktime_ms_delta(ktimeout, ktime);
if (completion_done(complete)) {
s64 delta = ktime_ms_delta(ktimeout, ktime);
return msecs_to_jiffies(delta) ?: 1;
return msecs_to_jiffies(delta) ?: 1;
}
}
ktime = ktime_get();
@ -1029,18 +1030,14 @@ tegra_i2c_wait_completion_timeout(struct tegra_i2c_dev *i2c_dev,
disable_irq(i2c_dev->irq);
/*
* Under some rare circumstances (like running KASAN +
* NFS root) CPU, which handles interrupt, may stuck in
* uninterruptible state for a significant time. In this
* case we will get timeout if I2C transfer is running on
* a sibling CPU, despite of IRQ being raised.
*
* In order to handle this rare condition, the IRQ status
* needs to be checked after timeout.
* There is a chance that completion may happen after IRQ
* synchronization, which is done by disable_irq().
*/
if (ret == 0)
ret = tegra_i2c_poll_completion_timeout(i2c_dev,
complete, 0);
if (ret == 0 && completion_done(complete)) {
dev_warn(i2c_dev->dev,
"completion done after timeout\n");
ret = 1;
}
}
return ret;