CHROMIUM: iwl7000: Fail fast if HW is inaccessible at probe
If the HW is not responding at probe time, fail immediately complaining
about it. Without this, we see that the kernel spends > 100ms trying to
load firmware (even gives an incorrect impression that it actually
loaded a firmware) and do unnecesary processing before concluding that
the device is not accessible:
INFO kernel: [ 34.092678] iwlwifi 0000:01:00.0: enabling device (0000 -> 0002)
WARNING kernel: [ 34.093560] iwlwifi 0000:01:00.0: Direct firmware load for iwl-dbg-cfg.ini failed with error -2
INFO kernel: [ 34.111523] iwlwifi 0000:01:00.0: loaded firmware version 17.318154.0 op_mode iwlmvm
INFO kernel: [ 34.173250] iwlwifi 0000:01:00.0: Detected Intel(R) Dual Band Wireless AC 7265, REV=0xFFFFFFFF
ERR kernel: [ 34.198023] iwlwifi 0000:01:00.0: iwlwifi transaction failed, dumping registers
ERR kernel: [ 34.198044] iwlwifi 0000:01:00.0: iwlwifi device config registers:
Signed-off-by: Rajat Jain <rajatja@google.com>
BUG=b:78586198
TEST=check it fails sooner if HW not accessible.
Change-Id: I4fb5fea510961f18ee1bc1404ee7f85a7c40b22e
Reviewed-on: https://chromium-review.googlesource.com/1038304
Commit-Ready: Kirtika Ruchandani <kirtika@chromium.org>
Tested-by: Rajat Jain <rajatja@chromium.org>
Reviewed-by: Rajat Jain <rajatja@chromium.org>
diff --git a/drivers/net/wireless/iwl7000/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwl7000/iwlwifi/pcie/trans.c
index 70e554a..16697c6 100644
--- a/drivers/net/wireless/iwl7000/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwl7000/iwlwifi/pcie/trans.c
@@ -3356,6 +3356,10 @@
iwl_disable_interrupts(trans);
trans->hw_rev = iwl_read32(trans, CSR_HW_REV);
+ if (trans->hw_rev == 0xffffffff) {
+ dev_err(&pdev->dev, "HW_REV=0xFFFFFFFF, PCI issues?\n");
+ goto out_no_pci;
+ }
/*
* In the 8000 HW family the format of the 4 bytes of CSR_HW_REV have
* changed, and now the revision step also includes bit 0-1 (no more
