This is a note to let you know that I've just added the patch titled AHCI: Fix softreset failed issue of Port Multiplier to the 4.3-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ahci-fix-softreset-failed-issue-of-port-multiplier.patch and it can be found in the queue-4.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 023113d24ef9e1d2b44cb2446872b17e2b01d8b1 Mon Sep 17 00:00:00 2001 From: Xiangliang Yu <Xiangliang.Yu@xxxxxxx> Date: Thu, 26 Nov 2015 20:27:02 +0800 Subject: AHCI: Fix softreset failed issue of Port Multiplier From: Xiangliang Yu <Xiangliang.Yu@xxxxxxx> commit 023113d24ef9e1d2b44cb2446872b17e2b01d8b1 upstream. Current code doesn't update port value of Port Multiplier(PM) when sending FIS of softreset to device, command will fail if FBS is enabled. There are two ways to fix the issue: the first is to disable FBS before sending softreset command to PM device and the second is to update port value of PM when sending command. For the first way, i can't find any related rule in AHCI Spec. The second way can avoid disabling FBS and has better performance. Signed-off-by: Xiangliang Yu <Xiangliang.Yu@xxxxxxx> Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/ata/libahci.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -1266,6 +1266,15 @@ static int ahci_exec_polled_cmd(struct a ata_tf_to_fis(tf, pmp, is_cmd, fis); ahci_fill_cmd_slot(pp, 0, cmd_fis_len | flags | (pmp << 12)); + /* set port value for softreset of Port Multiplier */ + if (pp->fbs_enabled && pp->fbs_last_dev != pmp) { + tmp = readl(port_mmio + PORT_FBS); + tmp &= ~(PORT_FBS_DEV_MASK | PORT_FBS_DEC); + tmp |= pmp << PORT_FBS_DEV_OFFSET; + writel(tmp, port_mmio + PORT_FBS); + pp->fbs_last_dev = pmp; + } + /* issue & wait */ writel(1, port_mmio + PORT_CMD_ISSUE); Patches currently in stable-queue which might be from Xiangliang.Yu@xxxxxxx are queue-4.3/ahci-fix-softreset-failed-issue-of-port-multiplier.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html