diff options
Diffstat (limited to 'target/linux/mvebu/patches-3.10/0085-irqchip-armada-370-xp-fix-IPI-race-condition.patch')
| -rw-r--r-- | target/linux/mvebu/patches-3.10/0085-irqchip-armada-370-xp-fix-IPI-race-condition.patch | 46 |
1 files changed, 0 insertions, 46 deletions
diff --git a/target/linux/mvebu/patches-3.10/0085-irqchip-armada-370-xp-fix-IPI-race-condition.patch b/target/linux/mvebu/patches-3.10/0085-irqchip-armada-370-xp-fix-IPI-race-condition.patch deleted file mode 100644 index 336ad8d..0000000 --- a/target/linux/mvebu/patches-3.10/0085-irqchip-armada-370-xp-fix-IPI-race-condition.patch +++ /dev/null @@ -1,46 +0,0 @@ -From 60b78d28057f9f1ecce39955755d26e4cd3130de Mon Sep 17 00:00:00 2001 -From: Lior Amsalem <alior@marvell.com> -Date: Mon, 25 Nov 2013 17:26:44 +0100 -Subject: [PATCH 085/203] irqchip: armada-370-xp: fix IPI race condition - -In the Armada 370/XP driver, when we receive an IRQ 0, we read the -list of doorbells that caused the interrupt from register -ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS. This gives the list of IPIs that -were generated. However, instead of acknowledging only the IPIs that -were generated, we acknowledge *all* the IPIs, by writing -~IPI_DOORBELL_MASK in the ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS register. - -This creates a race condition: if a new IPI that isn't part of the -ones read into the temporary "ipimask" variable is fired before we -acknowledge all IPIs, then we will simply loose it. This is causing -scheduling hangs on SMP intensive workloads. - -It is important to mention that this ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS -register has the following behavior: "A CPU write of 0 clears the bits -in this field. A CPU write of 1 has no effect". This is what allows us -to simply write ~ipimask to acknoledge the handled IPIs. - -Notice that the same problem is present in the MSI implementation, but -it will be fixed as a separate patch, so that this IPI fix can be -pushed to older stable versions as appropriate (all the way to 3.8), -while the MSI code only appeared in 3.13. - -Signed-off-by: Lior Amsalem <alior@marvell.com> -Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> -Cc: stable@vger.kernel.org -Cc: Thomas Gleixner <tglx@linutronix.de> ---- - drivers/irqchip/irq-armada-370-xp.c | 2 +- - 1 file changed, 1 insertion(+), 1 deletion(-) - ---- a/drivers/irqchip/irq-armada-370-xp.c -+++ b/drivers/irqchip/irq-armada-370-xp.c -@@ -407,7 +407,7 @@ armada_370_xp_handle_irq(struct pt_regs - ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS) - & IPI_DOORBELL_MASK; - -- writel(~IPI_DOORBELL_MASK, per_cpu_int_base + -+ writel(~ipimask, per_cpu_int_base + - ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS); - - /* Handle all pending doorbells */ |