[PATCH 5.10 004/199] i2c: tegra: Wait for config load atomically while in ISR

Greg Kroah-Hartman
2021-01-26T09:22:51Z

From: Mikko Perttunen <mperttunen@nvidia.com>

commit 27b7c6e096264cc7b91bb80a4f65f8c0a66f079f upstream.

Upon a communication error, the interrupt handler can call
tegra_i2c_disable_packet_mode. This causes a sleeping poll to happen
unless the current transaction was marked atomic. Fix this by
making the poll happen atomically if we are in an IRQ.

This matches the behavior prior to the patch mentioned
in the Fixes tag.

Fixes: ede2299f7101 ("i2c: tegra: Support atomic transfers")
Cc: stable@vger.kernel.org
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/i2c/busses/i2c-tegra.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -533,7 +533,7 @@ static int tegra_i2c_poll_register(struc
void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg);
u32 val;

- if (!i2c_dev->atomic_mode)
+ if (!i2c_dev->atomic_mode && !in_irq())
return readl_relaxed_poll_timeout(addr, val, !(val & mask),
delay_us, timeout_us);