[PATCH] serial/amba-pl011: Disable interrupts around TX softirq
From: Dave.Martin@arm.com (Dave P Martin)
Date: 2015-06-23 11:13:14
Also in:
linux-serial, stable
From: Dave.Martin@arm.com (Dave P Martin)
Date: 2015-06-23 11:13:14
Also in:
linux-serial, stable
On Sat, Jun 20, 2015 at 10:09:37AM +0100, Stefan Wahren wrote:
quoted
Dave Martin [off-list ref] hat am 18. Juni 2015 um 15:54 geschrieben: pl011_tx_softirq() currently uses spin_{,un}lock(), which are not sufficient to inhibit pl011_int() from being triggered by a local IRQ and trying to re-take the same lock. This can lead to deadlocks. This patch uses the _irq() locking variants instead to ensure that pl011_int() handling for a given port is deferred until any pl011_tx_softirq() work for that port is complete. Fixes: 734745caeb9f serial/amba-pl011: Activate TX IRQ passively Signed-off-by: Dave Martin <Dave.Martin@arm.com> Tested-by: Robin Murphy <robin.murphy@arm.com> Cc: stable <redacted> # 4.1I also get info messages about inconsistent lock state on my mx28 board, after applying the patch the messages disappeared. Tested-by: Stefan Wahren <redacted>
Thanks for the confirmation. Cheers ---Dave