[PATCH 2/5] PCI/switchtec: Fix a MRPC error status handling issue

From: kelvin.cao
Date: Fri Sep 24 2021 - 00:15:54 EST


From: Kelvin Cao <kelvin.cao@xxxxxxxxxxxxx>

If an error is encountered when executing a MRPC command, the firmware
will set the status register to SWITCHTEC_MRPC_STATUS_ERROR and return
the error code in the return value register.

Add handling of SWITCHTEC_MRPC_STATUS_ERROR on status register when
completing a MRPC command.

Signed-off-by: Kelvin Cao <kelvin.cao@xxxxxxxxxxxxx>
---
drivers/pci/switch/switchtec.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
index 092653487021..76f14ed15445 100644
--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -230,7 +230,8 @@ static void mrpc_complete_cmd(struct switchtec_dev *stdev)
stuser_set_state(stuser, MRPC_DONE);
stuser->return_code = 0;

- if (stuser->status != SWITCHTEC_MRPC_STATUS_DONE)
+ if (stuser->status != SWITCHTEC_MRPC_STATUS_DONE &&
+ stuser->status != SWITCHTEC_MRPC_STATUS_ERROR)
goto out;

if (stdev->dma_mrpc)
@@ -614,7 +615,8 @@ static ssize_t switchtec_dev_read(struct file *filp, char __user *data,
out:
mutex_unlock(&stdev->mrpc_mutex);

- if (stuser->status == SWITCHTEC_MRPC_STATUS_DONE)
+ if (stuser->status == SWITCHTEC_MRPC_STATUS_DONE ||
+ stuser->status == SWITCHTEC_MRPC_STATUS_ERROR)
return size;
else if (stuser->status == SWITCHTEC_MRPC_STATUS_INTERRUPTED)
return -ENXIO;
--
2.25.1