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| author | Kelvin Cao <kelvin.cao@microchip.com> | 2018-12-10 17:12:20 +0800 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2018-12-12 16:30:03 -0600 |
| commit | 526180408b815aa7b96fd48bd23cdd33ef04e38e (patch) | |
| tree | 35e3b8150d4ad8da5e6d9e41b030f02c3e96b896 /drivers/pci | |
| parent | 651022382c7f8da46cb4872a545ee1da6d097d2a (diff) | |
| download | linux-526180408b815aa7b96fd48bd23cdd33ef04e38e.tar.gz linux-526180408b815aa7b96fd48bd23cdd33ef04e38e.tar.bz2 linux-526180408b815aa7b96fd48bd23cdd33ef04e38e.zip | |
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')
| -rw-r--r-- | drivers/pci/switch/switchtec.c | 4 |
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)); } |