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authorWolfram Sang <wsa@the-dreams.de>2020-04-27 10:52:22 +0200
committerWolfram Sang <wsa@the-dreams.de>2020-04-28 13:31:17 +0200
commit8839e4605eacfc711b775c90f24b62149bf6574e (patch)
tree7f193e54ab80e4db930e68caf454e6f450d651f0 /drivers
parentRevert "i2c: tegra: Synchronize DMA before termination" (diff)
downloadlinux-dev-8839e4605eacfc711b775c90f24b62149bf6574e.tar.xz
linux-dev-8839e4605eacfc711b775c90f24b62149bf6574e.zip
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 <treding@nvidia.com> Link: https://lore.kernel.org/dmaengine/20200319201140.17451-1-digetx@gmail.com/ Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i2c/busses/i2c-tegra.c27
1 files 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;