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authorKelvin Cao <kelvin.cao@microchip.com>2018-12-10 17:12:20 +0800
committerBjorn Helgaas <bhelgaas@google.com>2018-12-12 16:30:03 -0600
commit526180408b815aa7b96fd48bd23cdd33ef04e38e (patch)
tree35e3b8150d4ad8da5e6d9e41b030f02c3e96b896 /drivers/pci/switch
parent651022382c7f8da46cb4872a545ee1da6d097d2a (diff)
downloadlinux-526180408b815aa7b96fd48bd23cdd33ef04e38e.tar.bz2
switchtec: Remove immediate status check after submitting MRPC command
After submitting a Firmware Download MRPC command, Switchtec firmware will delay Management EP BAR MemRd TLP responses by more than 10ms. This is a firmware limitation. Delayed MemRd completions are a problem for systems with a low Completion Timeout (CTO). The current driver checks the MRPC status immediately after submitting an MRPC command, which results in a delayed MemRd completion that may cause a Completion Timeout. Remove the immediate status check and rely on the check after receiving an interrupt or timing out. This is only a software workaround to the READ issue and a proper fix of this should be done in firmware. Fixes: 080b47def5e5 ("MicroSemi Switchtec management interface driver") Signed-off-by: Kelvin Cao <kelvin.cao@microchip.com> Signed-off-by: Wesley Sheng <wesley.sheng@microchip.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Diffstat (limited to 'drivers/pci/switch')
-rw-r--r--drivers/pci/switch/switchtec.c4
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/pci/switch/switchtec.c b/drivers/pci/switch/switchtec.c
index 54a8b30dda38..d2bca2dd9889 100644
--- a/drivers/pci/switch/switchtec.c
+++ b/drivers/pci/switch/switchtec.c
@@ -134,10 +134,6 @@ static void mrpc_cmd_submit(struct switchtec_dev *stdev)
stuser->data, stuser->data_len);
iowrite32(stuser->cmd, &stdev->mmio_mrpc->cmd);
- stuser->status = ioread32(&stdev->mmio_mrpc->status);
- if (stuser->status != SWITCHTEC_MRPC_STATUS_INPROGRESS)
- mrpc_complete_cmd(stdev);
-
schedule_delayed_work(&stdev->mrpc_timeout,
msecs_to_jiffies(500));
}