kernel.git/drivers/ata/libahci.c, branch linux-4.0.y

libata: Add helper to determine when PHY events should be ignored

2015-06-06T15:21:02Z

commit 8393b811f38acdf7fd8da2028708edad3e68ce1f upstream. This is a preparation commit that will allow to add other criteria according to which PHY events should be dropped. Signed-off-by: Gabriele Mazzotta Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

ahci: Use dev_info() to inform about the lack of Device Sleep support

2015-01-09T22:04:12Z

According to the Serial ATA AHCI specification, Device Sleep is an optional feature and as such no errors should be printed if it's missing. Keep informing users, but use dev_info() instead of dev_err(). Signed-off-by: Gabriele Mazzotta Signed-off-by: Tejun Heo

Revert "AHCI: Optimize single IRQ interrupt processing"

2014-10-27T16:02:05Z

This reverts commit 18dcf433f3ded61eb140a55e7048ec2fef79e723. IRQF_ONESHOT was missing from the conversion causing screaming interrupts problems on some setups and LKP detected measureable drop in IO performance. It looks like we'll first need to drop the threaded IRQ handling first before splitting locking. Signed-off-by: Tejun Heo Cc: Alexander Gordeev Reported-by: kernel test robot Reported-by: Marc Zyngier Link: http://lkml.kernel.org/g/20141027021651.GF27038@yliu-dev.sh.intel.com Link: http://lkml.kernel.org/g/1414082970-20775-1-git-send-email-marc.zyngier@arm.com

Revert "AHCI: Do not acquire ata_host::lock from single IRQ handler"

2014-10-27T16:00:01Z

This reverts commit 33fb0d01ce60fe4c0c12c4f0c134c5cdb818ac5a. 18dcf433f3de ("AHCI: Optimize single IRQ interrupt processing") is scheduled to be reverted. This is an optimization dependent on the mentioned commit. Revert it first. Signed-off-by: Tejun Heo

AHCI: Do not acquire ata_host::lock from single IRQ handler

2014-10-06T15:43:36Z

There is no need to acquire ata_host::lock spinlock from hardware context single IRQ interrupt handler since the handler does not access host data that could be altered by concurrent processors. Signed-off-by: Alexander Gordeev Signed-off-by: Tejun Heo Cc: linux-ide@vger.kernel.org

AHCI: Optimize single IRQ interrupt processing

2014-10-06T15:43:36Z

Split interrupt service routine into hardware context handler and threaded context handler. That allows to protect ports with individual locks rather than with a single host-wide lock and move port interrupts handling out of the hardware interrupt context. Testing was done by transferring 8GB on two hard drives in parallel using command 'dd if=/dev/sd{a,b} of=/dev/null'. With lock_stat statistics I measured access times to ata_host::lock spinlock (since interrupt handler code is fully embraced with this lock). The average lock's holdtime decreased eight times while average waittime decreased two times. Both before and after the change the transfer time is the same, while 'perf record -e cycles:k ...' shows 1%-4% CPU time spent in ahci_single_irq_intr() routine before the update and not even sampled/shown ahci_single_irq_intr() after the update. Signed-off-by: Alexander Gordeev Signed-off-by: Tejun Heo Cc: linux-ide@vger.kernel.org

AHCI: Do not read HOST_IRQ_STAT reg in multi-MSI mode

2014-10-06T15:43:36Z

As described in AHCI v1.0 specification chapter 10.6.2.2 "Multiple MSI Based Messages" generation of interrupts is not controlled through the HOST_IRQ_STAT register. Considering MMIO access is expensive remove unnecessary reading and writing of HOST_IRQ_STAT register. Further, serializing access to the host data is no longer needed and the interrupt service routine can avoid competing on the host lock. Signed-off-by: Alexander Gordeev Suggested-by: "Jiang, Dave" Signed-off-by: Tejun Heo Cc: "Jiang, Dave" Cc: linux-ide@vger.kernel.org

AHCI: Make few function names more descriptive

2014-10-06T15:43:35Z

Signed-off-by: Alexander Gordeev Signed-off-by: Tejun Heo Cc: linux-ide@vger.kernel.org

AHCI: Move host activation code into ahci_host_activate()

2014-10-06T15:43:35Z

Currently host activation done by calling either function ahci_host_activate() or ata_host_activate(). Consolidate the code by only calling ahci_host_activate() for all AHCI devices. Signed-off-by: Alexander Gordeev Signed-off-by: Tejun Heo Cc: linux-ide@vger.kernel.org

AHCI: Move ahci_host_activate() function to libahci.c

2014-10-06T15:43:34Z

This update is a prerequisite for consolidation of AHCI host activation code within ahci_host_activate() function. Signed-off-by: Alexander Gordeev Signed-off-by: Tejun Heo Cc: linux-ide@vger.kernel.org