linux/drivers/tty/hvc, branch v3.0.79

tty: hvc_dcc: Fix duplicate character inputs

2011-11-26T17:09:57Z

commit c2a3e84f950e7ddba1f3914b005861d46ae60359 upstream. Reading from the DCC grabs a character from the buffer and clears the status bit. Since this is a context-changing operation, instructions following the character read that rely on the status bit being accurate need to be synchronized with an ISB. In this case, the status bit check needs to execute after the character read otherwise we run the risk of reading the character and checking the status bit before the read can clear the status bit in the first place. When this happens, the user will see the same character they typed twice, instead of once. Add an ISB after the read and the write, so that the status check is synchronized with the read/write operations. Signed-off-by: Stephen Boyd Signed-off-by: Greg Kroah-Hartman

hvc_console: Improve tty/console put_chars handling

2011-08-05T04:58:41Z

commit 8c2381af0d3ef62a681dac5a141b6dabb27bf2e1 upstream. Currently, the hvc_console_print() function drops console output if the hvc backend's put_chars() returns 0. This patch changes this behavior to allow a retry through returning -EAGAIN. This change also affects the hvc_push() function. Both functions are changed to handle -EAGAIN and to retry the put_chars() operation. If a hvc backend returns -EAGAIN, the retry handling differs: - hvc_console_print() spins to write the complete console output. - hvc_push() behaves the same way as for returning 0. Now hvc backends can indirectly control the way how console output is handled through the hvc console layer. Signed-off-by: Hendrik Brueckner Acked-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman

Fix common misspellings

2011-03-31T14:26:23Z

Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi

drivers: Final irq namespace conversion

2011-03-29T12:48:19Z

Scripted with coccinelle. Signed-off-by: Thomas Gleixner

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2011-03-18T17:37:40Z

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits) doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore Update cpuset info & webiste for cgroups dcdbas: force SMI to happen when expected arch/arm/Kconfig: remove one to many l's in the word. asm-generic/user.h: Fix spelling in comment drm: fix printk typo 'sracth' Remove one to many n's in a word Documentation/filesystems/romfs.txt: fixing link to genromfs drivers:scsi Change printk typo initate -> initiate serial, pch uart: Remove duplicate inclusion of linux/pci.h header fs/eventpoll.c: fix spelling mm: Fix out-of-date comments which refers non-existent functions drm: Fix printk typo 'failled' coh901318.c: Change initate to initiate. mbox-db5500.c Change initate to initiate. edac: correct i82975x error-info reported edac: correct i82975x mci initialisation edac: correct commented info fs: update comments to point correct document target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c ... Trivial conflict in fs/eventpoll.c (spelling vs addition)

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2011-03-18T13:31:43Z

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (62 commits) powerpc/85xx: Fix signedness bug in cache-sram powerpc/fsl: 85xx: document cache sram bindings powerpc/fsl: define binding for fsl mpic interrupt controllers powerpc/fsl_msi: Handle msi-available-ranges better drivers/serial/ucc_uart.c: Add of_node_put to avoid memory leak powerpc/85xx: Fix SPE float to integer conversion failure powerpc/85xx: Update sata controller compatible for p1022ds board ATA: Add FSL sata v2 controller support powerpc/mpc8xxx_gpio: simplify searching for 'fsl, qoriq-gpio' compatiable powerpc/8xx: remove obsolete mgsuvd board powerpc/82xx: rename and update mgcoge board support powerpc/83xx: rename and update kmeter1 powerpc/85xx: Workaroudn e500 CPU erratum A005 powerpc/fsl_pci: Add support for FSL PCIe controllers v2.x powerpc/85xx: Fix writing to spin table 'cpu-release-addr' on ppc64e powerpc/pseries: Disable MSI using new interface if possible powerpc: Enable GENERIC_HARDIRQS_NO_DEPRECATED. powerpc: core irq_data conversion. powerpc: sysdev/xilinx_intc irq_data conversion. powerpc: sysdev/uic irq_data conversion. ... Fix up conflicts in arch/powerpc/sysdev/fsl_msi.c (due to getting rid of of_platform_driver in arch/powerpc)

Merge branches 'stable/hvc-console', 'stable/gntalloc.v6' and 'stable/balloon' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

2011-03-18T01:16:36Z

* 'stable/hvc-console' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/hvc: Disable probe_irq_on/off from poking the hvc-console IRQ line. * 'stable/gntalloc.v6' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen: gntdev: fix build warning xen/p2m/m2p/gnttab: do not add failed grant maps to m2p override xen-gntdev: Add cast to pointer xen-gntdev: Fix incorrect use of zero handle xen: change xen/[gntdev/gntalloc] to default m xen-gntdev: prevent using UNMAP_NOTIFY_CLEAR_BYTE on read-only mappings xen-gntdev: Avoid double-mapping memory xen-gntdev: Avoid unmapping ranges twice xen-gntdev: Use map->vma for checking map validity xen-gntdev: Fix unmap notify on PV domains xen-gntdev: Fix memory leak when mmap fails xen/gntalloc,gntdev: Add unmap notify ioctl xen-gntalloc: Userspace grant allocation driver xen-gntdev: Support mapping in HVM domains xen-gntdev: Add reference counting to maps xen-gntdev: Use find_vma rather than iterating our vma list manually xen-gntdev: Change page limit to be global instead of per-open * 'stable/balloon' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (24 commits) xen-gntdev: Use ballooned pages for grant mappings xen-balloon: Add interface to retrieve ballooned pages xen-balloon: Move core balloon functionality out of module xen/balloon: Remove pr_info's and don't alter retry_count xen/balloon: Protect against CPU exhaust by event/x process xen/balloon: Migration from mod_timer() to schedule_delayed_work() xen/balloon: Removal of driver_pages

xen/hvc: Disable probe_irq_on/off from poking the hvc-console IRQ line.

2011-03-10T05:57:59Z

This fixes a particular nasty racing problem found when using Xen hypervisor with the console (hvc) output being routed to the serial port and the serial port receiving data when probe_irq_off(probe_irq_on) is running. Specifically the bug manifests itself with: [ 4.470693] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 4.470693] IP: [] handle_IRQ_event+0xe/0xc9 ..snip.. [ 4.470693] Call Trace: [ 4.470693] [ 4.470693] [] handle_percpu_irq+0x3c/0x69 [ 4.470693] [] __xen_evtchn_do_upcall+0xfd/0x195 [ 4.470693] [] ? xen_restore_fl_direct_end+0x0/0x1 [ 4.470693] [] xen_evtchn_do_upcall+0x32/0x47 [ 4.470693] [] xen_do_hypervisor_callback+0x1e/0x30 [ 4.470693] [ 4.470693] [] ? hypercall_page+0x22a/0x1000 [ 4.470693] [] ? hypercall_page+0x22a/0x1000 [ 4.470693] [] ? xen_force_evtchn_callback+0xd/0xf [ 4.470693] [] ? check_events+0x12/0x20 [ 4.470693] [] ? xen_irq_enable_direct_end+0x0/0x7 [ 4.470693] [] ? probe_irq_on+0x8f/0x1d7 [ 4.470693] [] ? serial8250_config_port+0x7b7/0x9e6 [ 4.470693] [] ? uart_add_one_port+0x11b/0x305 The bug is trigged by three actors working together: A). serial_8250_config_port calling probe_irq_off(probe_irq_on()) wherein all of the IRQ handlers are being started and shut off. The functions utilize the sleep functions so the minimum time they are run is 120 msec. B). Xen hypervisor receiving on the serial line any character and setting the bits in the event channel - during this 120 msec timeframe. C). The hvc API makes a call to 'request_irq' (and hence setting desc->action to a valid value), much much later - when user space opens /dev/console (hvc_open). To make the console usable during bootup, the Xen HVC implementation sets the IRQ chip (and correspondingly the event channel) much earlier. The IRQ chip handler that is used is the handle_percpu_irq (aaca49642b92c8a57d3ca5029a5a94019c7af69f) Back to the issue. When A) is being called it ends up calling the xen_percpu_chip's chip->startup twice and chip->shutdown once. Those are set to the default_startup and mask_irq (events.c) respectivly. If (and this seems to depend on what serial concentrator you use), B) gets data from the serial port it sets in the event channel a pending bit. When A) calls chip->startup(), the masking of the pending bit, and unmasking of the event channel mask, and also setting of the upcall_pending flag is done (since there is data present on the event channel). If before the 120 msec has elapsed, any IRQ handler (Xen IRQ has one IRQ handler, which checks the event channels bitmap to figure which one to call) is called we end up calling the handle_percpu_irq. The handle_percpu_irq calls desc->action (which is NULL) and we blow up. Caveats: I could only reproduce this on 2.6.32 pvops. I am not sure why this is not showing up on 2.6.38 kernel. The probe_irq_on/off has code to disable poking specific IRQ lines. This is done by using the set_irq_noprobe() and then we do not have to worry about the handle_percpu_irq being called before the IRQ action handler has been installed. Signed-off-by: Konrad Rzeszutek Wilk

powerpc/pseries: Reduce HVCS driver insanity

2011-03-02T05:50:25Z

The HVCS driver, for those who don't know, is a driver for the "server" side of the IBM virtual terminal mechanism allowing Linux partitions to act as terminal servers under IBM PowerVM hypervisor. It's almost never used on the field at the moment. However, it's part of our configs, and in its current incarnation, will allocate the tty driver & major (with 64 minors) and create a kernel thread whether it's used or not, ie, whether the hypervisor did put a virtual terminal server device node in the partition or not (or whether running on a pseries machine or not even). This in turns causes modern distro's udev's to start trying to open all those 64 minors at boot, which, since they aren't linked to anything, causes the driver to spew errors in the kernel log for each of them. Not nice. This moves all that initialization to a function which is now only called the first time a terminal server virtual IO device is actually probed (that is almost never). There's still a _LOT_ of cleanup that can be done in this driver, some simple (almost all printk's statements in there shall either just be removed or in some case turned into better written & more informative messages, including using the dev_* variants etc...). This is left as an exercise for whoever actually cares about that driver. One could also try to be smart and dispose of all the tty related resources when the last instance of the VIO server device is removed (Hotplug anybody ?). Signed-off-by: Benjamin Herrenschmidt

Merge 2.6.38-rc6 into tty-next

2011-02-24T19:36:31Z

This was to resolve a merge issue with drivers/char/Makefile and drivers/tty/serial/68328serial.c Signed-off-by: Greg Kroah-Hartman