From aeb8a3d16ae0faceeae77adde2d3f9f2b199f4d9 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 12 Nov 2014 10:25:37 +0100 Subject: [PATCH] i2c: i801: Check if interrupts are disabled There is a control bit in the PCI configuration space which disables interrupts. If this bit is set, the driver should not try to make use of interrupts, it won't receive any. Signed-off-by: Jean Delvare Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-i801.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index a6f3bc38fbe5..3f1f30313cd7 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -109,12 +109,16 @@ /* PCI Address Constants */ #define SMBBAR 4 +#define SMBPCICTL 0x004 #define SMBPCISTS 0x006 #define SMBHSTCFG 0x040 /* Host status bits for SMBPCISTS */ #define SMBPCISTS_INTS 0x08 +/* Control bits for SMBPCICTL */ +#define SMBPCICTL_INTDIS 0x0400 + /* Host configuration bits for SMBHSTCFG */ #define SMBHSTCFG_HST_EN 1 #define SMBHSTCFG_SMB_SMI_EN 2 @@ -1231,6 +1235,22 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) /* Default timeout in interrupt mode: 200 ms */ priv->adapter.timeout = HZ / 5; + if (priv->features & FEATURE_IRQ) { + u16 pcictl, pcists; + + /* Complain if an interrupt is already pending */ + pci_read_config_word(priv->pci_dev, SMBPCISTS, &pcists); + if (pcists & SMBPCISTS_INTS) + dev_warn(&dev->dev, "An interrupt is pending!\n"); + + /* Check if interrupts have been disabled */ + pci_read_config_word(priv->pci_dev, SMBPCICTL, &pcictl); + if (pcictl & SMBPCICTL_INTDIS) { + dev_info(&dev->dev, "Interrupts are disabled\n"); + priv->features &= ~FEATURE_IRQ; + } + } + if (priv->features & FEATURE_IRQ) { init_waitqueue_head(&priv->waitq); -- 2.20.1