[PATCH 1/2] ACPI: EC: Abort address space access upon error

[Armin Wolf <W_Armin@gmx.de>]

Then 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>
---
 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 e7793ee9e649..a68dce2147a4 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -1333,10 +1333,13 @@ 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);
--
2.39.2