3bbc3c72c4
The imx6 PCI host controller suffers from a HW integration bug whereby the MSI enable bit in the root port MSI capability enables/disables MSIs interrupts for all downstream components in the PCI tree. This requires, as implemented in 75cb8d20c112 ("PCI: imx: Enable MSI from downstream components") that the root port MSI enable bit should be set in order for downstream PCI devices MSIs to function. The MSI enable bit programming might be lost during the suspend and should be re-stored during resume. Save the MSI control during suspend and restore it in resume. Link: https://lore.kernel.org/r/1670479534-22154-1-git-send-email-hongxing.zhu@nxp.com Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com> [lpieralisi@kernel.org: commit log] Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>