firmware: arm_scmi: Add missing Rx size re-initialisation

[ Upstream commit 9724722fde8f9bbd2b87340f00b9300c9284001e ]

Few commands provide the list of description partially and require
to be called consecutively until all the descriptors are fetched
completely. In such cases, we don't release the buffers and reuse
them for consecutive transmits.

However, currently we don't reset the Rx size which will be set as
per the response for the last transmit. This may result in incorrect
response size being interpretted as the firmware may repond with size
greater than the one set but we read only upto the size set by previous
response.

Let us reset the receive buffer size to max possible in such cases as
we don't know the exact size of the response.

Link:  https://lore.kernel.org/r/20201012141746.32575-1-sudeep.holla@arm.com
Fixes: b6f20ff8bd94 ("firmware: arm_scmi: add common infrastructure and support for base protocol")
Reported-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index 9853bd3c4d456b490855a36425935b29378427c6..017e5d8bd869a752d14bd7cdf58032e9d8a96787 100644 (file)
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -197,6 +197,8 @@ static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
                        protocols_imp[tot_num_ret + loop] = *(list + loop);
 
                tot_num_ret += loop_num_ret;
+
+               scmi_reset_rx_to_maxsz(handle, t);
        } while (loop_num_ret);
 
        scmi_xfer_put(handle, t);

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 75e39882746e1060eed0b786eb2c70c32f463a0b..fa3ad3a150c363542c6df8c7e10e09f6a54c6a7a 100644 (file)
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -192,6 +192,8 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
                }
 
                tot_rate_cnt += num_returned;
+
+               scmi_reset_rx_to_maxsz(handle, t);
                /*
                 * check for both returned and remaining to avoid infinite
                 * loop due to buggy firmware

diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index c113e578cc6ced05c46f2611098369696bd00403..6db59a7ac8531947dad7b82b66eb9fa066339979 100644 (file)
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -147,6 +147,8 @@ int scmi_do_xfer_with_response(const struct scmi_handle *h,
                               struct scmi_xfer *xfer);
 int scmi_xfer_get_init(const struct scmi_handle *h, u8 msg_id, u8 prot_id,
                       size_t tx_size, size_t rx_size, struct scmi_xfer **p);
+void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle,
+                           struct scmi_xfer *xfer);
 int scmi_handle_put(const struct scmi_handle *handle);
 struct scmi_handle *scmi_handle_get(struct device *dev);
 void scmi_set_handle(struct scmi_device *scmi_dev);

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 03ec74242c141ecff333a1256049e8de907124d7..28a3e4902ea4e21200727d7a023dd88d2dfa4ec4 100644 (file)
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -402,6 +402,14 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
        return ret;
 }
 
+void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle,
+                           struct scmi_xfer *xfer)
+{
+       struct scmi_info *info = handle_to_scmi_info(handle);
+
+       xfer->rx.len = info->desc->max_msg_size;
+}
+
 #define SCMI_MAX_RESPONSE_TIMEOUT      (2 * MSEC_PER_SEC)
 
 /**

diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
index 3e1e87012c95b4c5852ea1235dfa4818c440e4e8..3e8b548a12b622d552ca6933b3a3e3c8144de899 100644 (file)
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -304,6 +304,8 @@ scmi_perf_describe_levels_get(const struct scmi_handle *handle, u32 domain,
                }
 
                tot_opp_cnt += num_returned;
+
+               scmi_reset_rx_to_maxsz(handle, t);
                /*
                 * check for both returned and remaining to avoid infinite
                 * loop due to buggy firmware

diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index 1af0ad362e823c141d45a52400ea4f965c5b4591..4beee439b84ba2c51ddf87e2a9dc32c2eeab8b8e 100644 (file)
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -166,6 +166,8 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
                }
 
                desc_index += num_returned;
+
+               scmi_reset_rx_to_maxsz(handle, t);
                /*
                 * check for both returned and remaining to avoid infinite
                 * loop due to buggy firmware