From patchwork Mon Oct 2 18:31:24 2017
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Subject: ahci: don't ignore result code of ahci_reset_controller()
X-Patchwork-Submitter: Ard Biesheuvel <ard.biesheuvel@linaro.org>
X-Patchwork-Id: 820637
X-Patchwork-Delegate: davem@davemloft.net
Message-Id: <20171002183124.17003-1-ard.biesheuvel@linaro.org>
To: linux-ide@vger.kernel.org, tj@kernel.org
Cc: graeme.gregory@linaro.org, leif.lindholm@linaro.org,
daniel.thompson@Linaro.org, Ard Biesheuvel <ard.biesheuvel@linaro.org>
Date: Mon, 2 Oct 2017 19:31:24 +0100
From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
List-Id: <linux-ide.vger.kernel.org>
ahci_pci_reset_controller() calls ahci_reset_controller(), which may
fail, but ignores the result code and always returns success. This
may result in failures like below
ahci 0000:02:00.0: version 3.0
ahci 0000:02:00.0: enabling device (0000 -> 0003)
ahci 0000:02:00.0: SSS flag set, parallel bus scan disabled
ahci 0000:02:00.0: controller reset failed (0xffffffff)
ahci 0000:02:00.0: failed to stop engine (-5)
... repeated many times ...
ahci 0000:02:00.0: failed to stop engine (-5)
Unable to handle kernel paging request at virtual address ffff0000093f9018
...
PC is at ahci_stop_engine+0x5c/0xd8 [libahci]
LR is at ahci_deinit_port.constprop.12+0x1c/0xc0 [libahci]
...
[<ffff000000a17014>] ahci_stop_engine+0x5c/0xd8 [libahci]
[<ffff000000a196b4>] ahci_deinit_port.constprop.12+0x1c/0xc0 [libahci]
[<ffff000000a197d8>] ahci_init_controller+0x80/0x168 [libahci]
[<ffff000000a260f8>] ahci_pci_init_controller+0x60/0x68 [ahci]
[<ffff000000a26f94>] ahci_init_one+0x75c/0xd88 [ahci]
[<ffff000008430324>] local_pci_probe+0x3c/0xb8
[<ffff000008431728>] pci_device_probe+0x138/0x170
[<ffff000008585e54>] driver_probe_device+0x2dc/0x458
[<ffff0000085860e4>] __driver_attach+0x114/0x118
[<ffff000008583ca8>] bus_for_each_dev+0x60/0xa0
[<ffff000008585638>] driver_attach+0x20/0x28
[<ffff0000085850b0>] bus_add_driver+0x1f0/0x2a8
[<ffff000008586ae0>] driver_register+0x60/0xf8
[<ffff00000842f9b4>] __pci_register_driver+0x3c/0x48
[<ffff000000a3001c>] ahci_pci_driver_init+0x1c/0x1000 [ahci]
[<ffff000008083918>] do_one_initcall+0x38/0x120
where an obvious hardware level failure results in an unnecessary 15 second
delay and a subsequent crash.
So record the result code of ahci_reset_controller() and relay it, rather
than ignoring it.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
drivers/ata/ahci.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 5a5fd0b404eb..649e799df9c1 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -621,8 +621,11 @@ static void ahci_pci_save_initial_config(struct pci_dev *pdev,
static int ahci_pci_reset_controller(struct ata_host *host)
{
struct pci_dev *pdev = to_pci_dev(host->dev);
+ int rc;
- ahci_reset_controller(host);
+ rc = ahci_reset_controller(host);
+ if (rc)
+ return rc;
if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
struct ahci_host_priv *hpriv = host->private_data;