ASoC: SDCA: Correct FDL locking in sdca_fdl_process()

The current locking in sdca_fdl_process() locks over
sdca_ump_cancel_timeout() and the timeout work function takes the same
lock, this can lead to a deadlock if the work runs as part of the
cancel. To fix this use scoped_guard and move the cancel timeout to be
outside the lock.

Fixes: e92e25f77748 ("ASoC: SDCA: Add UMP timeout handling for FDL")
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Maciej Strozek <mstrozek@opensource.cirrus.com>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Tested-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://patch.msgid.link/20251120153023.2105663-5-ckeepax@opensource.cirrus.com
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sdca/sdca_fdl.c b/sound/soc/sdca/sdca_fdl.c
index cb79dc3131b82f80ac1f5af65c922a8c46ff2cd9..6568afacdf1a1d326a6a79b484651429d08d4023 100644 (file)
--- a/sound/soc/sdca/sdca_fdl.c
+++ b/sound/soc/sdca/sdca_fdl.c
@@ -402,8 +402,6 @@ int sdca_fdl_process(struct sdca_interrupt *interrupt)
        unsigned int reg, status;
        int response, ret;
 
-       guard(mutex)(&fdl_state->lock);
-
        ret = sdca_ump_get_owner_host(dev, interrupt->function_regmap,
                                      interrupt->function, interrupt->entity,
                                      interrupt->control);
@@ -412,56 +410,59 @@ int sdca_fdl_process(struct sdca_interrupt *interrupt)
 
        sdca_ump_cancel_timeout(&fdl_state->timeout);
 
-       reg = SDW_SDCA_CTL(interrupt->function->desc->adr, interrupt->entity->id,
-                          SDCA_CTL_XU_FDL_STATUS, 0);
-       ret = regmap_read(interrupt->function_regmap, reg, &status);
-       if (ret < 0) {
-               dev_err(dev, "failed to read FDL status: %d\n", ret);
-               return ret;
-       }
+       scoped_guard(mutex, &fdl_state->lock) {
+               reg = SDW_SDCA_CTL(interrupt->function->desc->adr,
+                                  interrupt->entity->id, SDCA_CTL_XU_FDL_STATUS, 0);
+               ret = regmap_read(interrupt->function_regmap, reg, &status);
+               if (ret < 0) {
+                       dev_err(dev, "failed to read FDL status: %d\n", ret);
+                       return ret;
+               }
 
-       dev_dbg(dev, "FDL status: %#x\n", status);
+               dev_dbg(dev, "FDL status: %#x\n", status);
 
-       ret = fdl_status_process(interrupt, status);
-       if (ret < 0)
-               goto reset_function;
-
-       response = ret;
+               ret = fdl_status_process(interrupt, status);
+               if (ret < 0)
+                       goto reset_function;
 
-       dev_dbg(dev, "FDL response: %#x\n", response);
+               response = ret;
 
-       ret = regmap_write(interrupt->function_regmap, reg,
-                          response | (status & ~SDCA_CTL_XU_FDLH_MASK));
-       if (ret < 0) {
-               dev_err(dev, "failed to set FDL status signal: %d\n", ret);
-               return ret;
-       }
+               dev_dbg(dev, "FDL response: %#x\n", response);
 
-       ret = sdca_ump_set_owner_device(dev, interrupt->function_regmap,
-                                       interrupt->function, interrupt->entity,
-                                       interrupt->control);
-       if (ret)
-               return ret;
-
-       switch (response) {
-       case SDCA_CTL_XU_FDLH_RESET_ACK:
-               dev_dbg(dev, "FDL request reset\n");
+               ret = regmap_write(interrupt->function_regmap, reg,
+                                  response | (status & ~SDCA_CTL_XU_FDLH_MASK));
+               if (ret < 0) {
+                       dev_err(dev, "failed to set FDL status signal: %d\n", ret);
+                       return ret;
+               }
 
-               switch (xu->reset_mechanism) {
-               default:
-                       dev_warn(dev, "Requested reset mechanism not implemented\n");
+               ret = sdca_ump_set_owner_device(dev, interrupt->function_regmap,
+                                               interrupt->function,
+                                               interrupt->entity,
+                                               interrupt->control);
+               if (ret)
+                       return ret;
+
+               switch (response) {
+               case SDCA_CTL_XU_FDLH_RESET_ACK:
+                       dev_dbg(dev, "FDL request reset\n");
+
+                       switch (xu->reset_mechanism) {
+                       default:
+                               dev_warn(dev, "Requested reset mechanism not implemented\n");
+                               fallthrough;
+                       case SDCA_XU_RESET_FUNCTION:
+                               goto reset_function;
+                       }
+               case SDCA_CTL_XU_FDLH_COMPLETE:
+                       if (status & SDCA_CTL_XU_FDLD_REQ_ABORT ||
+                           status == SDCA_CTL_XU_FDLD_COMPLETE)
+                               return 0;
                        fallthrough;
-               case SDCA_XU_RESET_FUNCTION:
-                       goto reset_function;
-               }
-       case SDCA_CTL_XU_FDLH_COMPLETE:
-               if (status & SDCA_CTL_XU_FDLD_REQ_ABORT ||
-                   status == SDCA_CTL_XU_FDLD_COMPLETE)
+               default:
+                       sdca_ump_schedule_timeout(&fdl_state->timeout, xu->max_delay);
                        return 0;
-               fallthrough;
-       default:
-               sdca_ump_schedule_timeout(&fdl_state->timeout, xu->max_delay);
-               return 0;
+               }
        }
 
 reset_function: