lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 6 Jul 2016 18:19:36 -0700 From: Greg Kroah-Hartman <gregkh@...uxfoundation.org> To: linux-kernel@...r.kernel.org Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, stable@...r.kernel.org, Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>, Mathias Nyman <mathias.nyman@...ux.intel.com> Subject: [PATCH 4.4 26/32] usb: xhci-plat: properly handle probe deferral for devm_clk_get() 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Petazzoni <thomas.petazzoni@...e-electrons.com> commit de95c40d5beaa47f6dc8fe9ac4159b4672b51523 upstream. On some platforms, the clocks might be registered by a platform driver. When this is the case, the clock platform driver may very well be probed after xhci-plat, in which case the first probe() invocation of xhci-plat will receive -EPROBE_DEFER as the return value of devm_clk_get(). The current code handles that as a normal error, and simply assumes that this means that the system doesn't have a clock for the XHCI controller, and continues probing without calling clk_prepare_enable(). Unfortunately, this doesn't work on systems where the XHCI controller does have a clock, but that clock is provided by another platform driver. In order to fix this situation, we handle the -EPROBE_DEFER error condition specially, and abort the XHCI controller probe(). It will be retried later automatically, the clock will be available, devm_clk_get() will succeed, and the probe() will continue with the clock prepared and enabled as expected. In practice, such issue is seen on the ARM64 Marvell 7K/8K platform, where the clocks are registered by a platform driver. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@...e-electrons.com> Signed-off-by: Mathias Nyman <mathias.nyman@...ux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org> --- drivers/usb/host/xhci-plat.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -132,6 +132,9 @@ static int xhci_plat_probe(struct platfo ret = clk_prepare_enable(clk); if (ret) goto put_hcd; + } else if (PTR_ERR(clk) == -EPROBE_DEFER) { + ret = -EPROBE_DEFER; + goto put_hcd; } if (of_device_is_compatible(pdev->dev.of_node,
Powered by blists - more mailing lists