Hi, I noticed that during initialization sata_mv.c assumes that the main interrupt mask has its default value of 0. The function mv_platform_probe(..) initializes a shadow irq mask with 0 assuming that's the value of the controller's register. Now mv_set_main_irq_mask(..) only writes the controller's register if the new value differs from the "shadowed" value. This is fatal when trying to disable all interrupts in mv_init_host(..), i.e. the following function call does not write anything to the main irq mask register: mv_set_main_irq_mask(host, ~0, 0); The effect I see on my machine (QNAP TS-109 II) with booting via kexec (with Linux as a 2nd-stage boot loader) is that if the sata_mv module was still loaded when performing kexec, then the new kernel's sata_mv module starts up with interrupts enabled. This results in an unhandled IRQ and breaks the boot process. The unhandled interrupt itself might also be fixed by Lennert's patch proposed at http://markmail.org/message/kwvzxstnlsa3s26w which I did not try yet. However I still propose to additionally initialize the shadow variable with the current contents of the main irq mask register to get both in sync and allow proper disabling the main irq mask. This fixes the unhandled irq on my machine. Signed-off-by: Thomas Reitmayr <treitmayr@xxxxxxxxxx> --- a/drivers/ata/sata_mv.c 2008-12-25 00:26:37.000000000 +0100 +++ b/drivers/ata/sata_mv.c 2009-01-24 18:48:17.000000000 +0100 @@ -3076,6 +3076,9 @@ static int mv_init_host(struct ata_host hpriv->main_irq_mask_addr = mmio + PCI_HC_MAIN_IRQ_MASK_OFS; } + /* initialize shadow irq mask with register's value */ + hpriv->main_irq_mask = readl(hpriv->main_irq_mask_addr); + /* global interrupt mask: 0 == mask everything */ mv_set_main_irq_mask(host, ~0, 0); -- Best regards, Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
