2016-10-19 19:47:50

by Thor Thayer

Subject: [PATCH] EDAC, altera: Disable IRQ while injecting SDRAM errors

From: Thor Thayer <[email protected]>

Disable IRQs while injecting SDRAM errors. The RT patches exposed
a spinlock deadlock where the spinlock taken for the regmap write
deadlocked with the IRQ clear regmap write.
Error injection is not normally enabled for ECC but only for
testing.

Signed-off-by: Thor Thayer <[email protected]>
---
drivers/edac/altera_edac.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index 58d3e2b..6421cc3 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -153,13 +153,17 @@ static ssize_t altr_sdr_mc_err_inject_write(struct file *file,
if (count == 3) {
edac_printk(KERN_ALERT, EDAC_MC,
"Inject Double bit error\n");
+ local_irq_disable();
regmap_write(drvdata->mc_vbase, priv->ce_ue_trgr_offset,
(read_reg | priv->ue_set_mask));
+ local_irq_enable();
} else {
edac_printk(KERN_ALERT, EDAC_MC,
"Inject Single bit error\n");
+ local_irq_disable();
regmap_write(drvdata->mc_vbase, priv->ce_ue_trgr_offset,
(read_reg | priv->ce_set_mask));
+ local_irq_enable();
}

ptemp[0] = 0x5A5A5A5A;
--
1.7.9.5

2016-10-22 18:14:32

by Borislav Petkov

Subject: Re: [PATCH] EDAC, altera: Disable IRQ while injecting SDRAM errors

On Wed, Oct 19, 2016 at 02:53:47PM -0500, [email protected] wrote:
> From: Thor Thayer <[email protected]>
>
> Disable IRQs while injecting SDRAM errors. The RT patches exposed
> a spinlock deadlock where the spinlock taken for the regmap write
> deadlocked with the IRQ clear regmap write.
> Error injection is not normally enabled for ECC but only for
> testing.
>
> Signed-off-by: Thor Thayer <[email protected]>
> ---
> drivers/edac/altera_edac.c | 4 ++++
> 1 file changed, 4 insertions(+)

Applied, thanks.

--
Regards/Gruss,
Boris.

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