From 8839e4605eacfc711b775c90f24b62149bf6574e Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 27 Apr 2020 10:52:22 +0200 Subject: [PATCH] Revert "i2c: tegra: Better handle case where CPU0 is busy for a long time" This reverts commit a900aeac253729411cf33c6cb598c152e9e4137f because regressions were showing up. Suggested-by: Thierry Reding Link: https://lore.kernel.org/dmaengine/20200319201140.17451-1-digetx@gmail.com/ Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-tegra.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index a795b4e278b1..4c4d17ddc96b 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -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;