[PATCH AUTOSEL 4.19 2/9] ACPI: EC: Abort address space access upon error

Sasha Levin
2024-06-18T12:43:22Z

From: Armin Wolf <W_Armin@gmx.de>

[ Upstream commit f6f172dc6a6d7775b2df6adfd1350700e9a847ec ]

When a multi-byte address space access is requested, acpi_ec_read()/
acpi_ec_write() is being called multiple times.

Abort such operations if a single call to acpi_ec_read() /
acpi_ec_write() fails, as the data read from / written to the EC
might be incomplete.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/acpi/ec.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index d2fde87e4d0d4..78f8b8b5a8099 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1330,10 +1330,13 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
if (ec->busy_polling || bits > 8)
acpi_ec_burst_enable(ec);

- for (i = 0; i < bytes; ++i, ++address, ++value)
+ for (i = 0; i < bytes; ++i, ++address, ++value) {
result = (function == ACPI_READ) ?
acpi_ec_read(ec, address, value) :
acpi_ec_write(ec, address, *value);
+ if (result < 0)
+ break;
+ }

if (ec->busy_polling || bits > 8)
acpi_ec_burst_disable(ec);
--
2.43.0