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When booting with a dock connected, the igc driver may get stuck for ~40
seconds if PCIe link is lost during initialization.
This happens because the driver access device after EECD register reads
return all F's, indicating failed reads. Consequently, hw->hw_addr is set
to NULL, which impacts subsequent rd32() reads. This leads to the driver
hanging in igc_get_hw_semaphore_i225(), as the invalid hw->hw_addr
prevents retrieving the expected value.
To address this, a validation check and a corresponding return value
catch is added for the EECD register read result. If all F's are
returned, indicating PCIe link loss, the driver will return -ENXIO
immediately. This avoids the 40-second hang and significantly improves
boot time when using a dock with an igc NIC.
Log before the patch:
[ 0.911913] igc 0000:70:00.0: enabling device (0000 -> 0002)
[ 0.912386] igc 0000:70:00.0: PTM enabled, 4ns granularity
[ 1.571098] igc 0000:70:00.0 (unnamed net_device) (uninitialized): PCIe link lost, device now detached
[ 43.449095] igc_get_hw_semaphore_i225: igc 0000:70:00.0 (unnamed net_device) (uninitialized): Driver can't access device - SMBI bit is set.
[ 43.449186] igc 0000:70:00.0: probe with driver igc failed with error -13
[ 46.345701] igc 0000:70:00.0: enabling device (0000 -> 0002)
[ 46.345777] igc 0000:70:00.0: PTM enabled, 4ns granularity
Log after the patch:
[ 1.031000] igc 0000:70:00.0: enabling device (0000 -> 0002)
[ 1.032097] igc 0000:70:00.0: PTM enabled, 4ns granularity
[ 1.642291] igc 0000:70:00.0 (unnamed net_device) (uninitialized): PCIe link lost, device now detached
[ 5.480490] igc 0000:70:00.0: enabling device (0000 -> 0002)
[ 5.480516] igc 0000:70:00.0: PTM enabled, 4ns granularity
Fixes: ab40561268 ("igc: Add NVM support")
Cc: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Signed-off-by: En-Wei Wu <en-wei.wu@canonical.com>
Reviewed-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.