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b25bcf1bca
Since the mvebu-soc-id code in mach-mvebu/ was introduced, several users have noticed a regression: the PCIe card connected in the first PCIe interface is not detected properly. This is due to the fact that the mvebu-soc-id code enables the PCIe clock of the first PCIe interface, reads the SoC device ID and revision number (yes this information is made available as part of PCIe registers), and then disables the clock. However, by doing this, we gate the clock and therefore loose the complex PCIe configuration that was done by the bootloader. Unfortunately, as of today, the kernel is not capable of doing this complex configuration by itself, so we really need to keep the PCIe clock enabled. However, we don't want to keep it enabled unconditionally: if the PCIe interface is not enabled or PCI support is not compiled into the kernel, there is no reason to keep the PCIe clock running. This issue was discussed with Kevin Hilman, and the suggested solution was to make the mvebu-soc-id code keep the clock enabled in case it will be needed for PCIe. This is therefore the solution implemented in this patch. Long term, we hope to make the kernel more capable in terms of PCIe configuration for this platform, which will anyway be needed to support the compilation of the PCIe host controller driver as a module. In the mean time however, we don't have much other choice than to implement the currently proposed solution. Reported-by: Neil Greatorex <neil@fatboyfat.co.uk> Cc: Neil Greatorex <neil@fatboyfat.co.uk> Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Cc: Kevin Hilman <khilman@linaro.org> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1399903900-29977-3-git-send-email-thomas.petazzoni@free-electrons.com Fixes: |
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| .. | ||
| include/mach | ||
| armada-370-xp.h | ||
| board-t5325.c | ||
| board-v7.c | ||
| board.h | ||
| coherency_ll.S | ||
| coherency.c | ||
| coherency.h | ||
| common.h | ||
| dove.c | ||
| headsmp.S | ||
| hotplug.c | ||
| Kconfig | ||
| kirkwood-pm.c | ||
| kirkwood-pm.h | ||
| kirkwood.c | ||
| kirkwood.h | ||
| Makefile | ||
| mvebu-soc-id.c | ||
| mvebu-soc-id.h | ||
| platsmp.c | ||
| pmsu.c | ||
| pmsu.h | ||
| system-controller.c | ||