linux/drivers/tty, branch v3.2.15

serial: sh-sci: fix a race of DMA submit_tx on transfer

2012-04-02T16:53:10Z

commit 49d4bcaddca977fffdea8b0b71f6e5da96dac78e upstream. When DMA is enabled, sh-sci transfer begins with uart_start() sci_start_tx() if (cookie_tx < 0) schedule_work() Then, starts DMA when wq scheduled, -- (A) process_one_work() work_fn_rx() cookie_tx = desc->submit_tx() And finishes when DMA transfer ends, -- (B) sci_dma_tx_complete() async_tx_ack() cookie_tx = -EINVAL (possible another schedule_work()) This A to B sequence is not reentrant, since controlling variables (for example, cookie_tx above) are not queues nor lists. So, they must be invoked as A B A B..., otherwise results in kernel crash. To ensure the sequence, sci_start_tx() seems to test if cookie_tx < 0 (represents "not used") to call schedule_work(). But cookie_tx will not be set (to a cookie, also means "used") until in the middle of work queue scheduled function work_fn_tx(). This gap between the test and set allows the breakage of the sequence under the very frequently call of uart_start(). Another gap between async_tx_ack() and another schedule_work() results in the same issue, too. This patch introduces a new condition "cookie_tx == 0" just to mark it is "busy" and assign it within spin-locked region to fill the gaps. Signed-off-by: Takashi Yoshii Reviewed-by: Guennadi Liakhovetski Signed-off-by: Paul Mundt Signed-off-by: Greg Kroah-Hartman

TTY: Wrong unicode value copied in con_set_unimap()

2012-04-02T16:52:31Z

commit 4a4c61b7ce26bfc9d49ea4bd121d52114bad9f99 upstream. Bugzilla 40012: PIO_UNIMAP bug: error updating Unicode-to-font map https://bugzilla.kernel.org/show_bug.cgi?id=40012 The unicode font map for the virtual console is a 32x32x64 table which allocates rows dynamically as entries are added. The unicode value increases sequentially and should count all entries even in empty rows. The defect is when copying the unicode font map in con_set_unimap(), the unicode value is not incremented properly. The wrong unicode value is entered in the new font map. Signed-off-by: Liz Clark Signed-off-by: Greg Kroah-Hartman

tty: moxa: fix bit test in moxa_start()

2012-04-02T16:52:31Z

commit 58112dfbfe02d803566a2c6c8bd97b5fa3c62cdc upstream. This is supposed to be doing a shift before the comparison instead of just doing a bitwise AND directly. The current code means the start() just returns without doing anything. Signed-off-by: Dan Carpenter Acked-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman

tty/powerpc: early udbg consoles can't be modules

2012-03-12T19:31:26Z

commit f21c6d4a49179f91fd70a41382382f08c780d425 upstream. Fixes these build errors: ERROR: ".udbg_printf" [drivers/tty/ehv_bytechan.ko] undefined! ERROR: ".register_early_udbg_console" [drivers/tty/ehv_bytechan.ko] undefined! ERROR: "udbg_putc" [drivers/tty/ehv_bytechan.ko] undefined! Cc: Timur Tabi Signed-off-by: Stephen Rothwell Signed-off-by: Greg Kroah-Hartman

drivers/tty/vt/vt_ioctl.c: fix KDFONTOP 32bit compatibility layer

2012-02-13T19:16:52Z

commit cbcb8346054073d000ecac324763372d6abd44ac upstream. KDFONTOP(GET) currently fails with EIO when being run in a 32bit userland with a 64bit kernel if the font width is not 8. This is because of the setting of the KD_FONT_FLAG_OLD flag, which makes con_font_get return EIO in such case. This flag should *not* be set for KDFONTOP, since it's actually the whole point of this flag (see comment in con_font_set for instance). Signed-off-by: Samuel Thibault Reviewed-by: Arnd Bergmann Cc: Arthur Taylor Cc: Jiri Slaby Cc: Jiri Olsa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

jsm: Fixed EEH recovery error

2012-02-03T17:22:07Z

commit 26aa38cafae0dbef3b2fe75ea487c83313c36d45 upstream. There was an error on the jsm driver that would cause it to be unable to recover after a second error is detected. At the first error, the device recovers properly: [72521.485691] EEH: Detected PCI bus error on device 0003:02:00.0 [72521.485695] EEH: This PCI device has failed 1 times in the last hour: ... [72532.035693] ttyn3 at MMIO 0x0 (irq = 49) is a jsm [72532.105689] jsm: Port 3 added However, at the second error, it cascades until EEH disables the device: [72631.229549] Call Trace: ... [72641.725687] jsm: Port 3 added [72641.725695] EEH: Detected PCI bus error on device 0003:02:00.0 [72641.725698] EEH: This PCI device has failed 3 times in the last hour: It was caused because the PCI state was not being saved after the first restore. Therefore, at the second recovery the PCI state would not be restored. Signed-off-by: Lucas Kannebley Tavares Signed-off-by: Breno Leitao Acked-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

serial: amba-pl011: lock console writes against interrupts

2012-02-03T17:22:07Z

commit ef605fdb33883d687cff5ba75095a91b313b4966 upstream. Protect against pl011_console_write() and the interrupt for the console UART running concurrently on different CPUs. Otherwise the console_write could spin for a long time waiting for the UART to become not busy, while the other CPU continuously services UART interrupts and keeps the UART busy. The checks for sysrq and oops_in_progress are taken from 8250.c. Signed-off-by: Rabin Vincent Reviewed-by: Srinidhi Kasagar Reviewed-by: Bibek Basu Reviewed-by: Shreshtha Kumar Sahu Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman

TTY: fix UV serial console regression

2012-02-03T17:22:06Z

commit 0eee50af5b13e00b3fb7a5fe8480419a71b8235d upstream. Commit 74c2107759d (serial: Use block_til_ready helper) and its fixup 3f582b8c110 (serial: fix termios settings in open) introduced a regression on UV systems. The serial eventually freezes while being used. It's completely unpredictable and sometimes needs a heap of traffic to happen first. To reproduce this, yast installation was used as it turned out to be pretty reliable in reproducing. Especially during installation process where one doesn't have an SSH daemon running. And no monitor as the HW is completely headless. So this was fun to find. Given the machine doesn't boot on vanilla before 2.6.36 final. (And the commits above are older.) Unless there is some bad race in the code, the hardware seems to be pretty broken. Otherwise pure MSR read should not cause such a bug, or? So to prevent the bug, revert to the old behavior. I.e. read modem status only if we really have to -- for non-CLOCAL set serials. Non-CLOCAL works on this hardware OK, I tried. See? I don't. And document that shit. Signed-off-by: Jiri Slaby References: https://lkml.org/lkml/2011/12/6/573 References: https://bugzilla.novell.com/show_bug.cgi?id=718518 Signed-off-by: Greg Kroah-Hartman

atmel_serial: fix spinlock lockup in RS485 code

2012-01-12T19:29:35Z

commit dbf1115d3f8c7052788aa4e6e46abd27f3b3eeba upstream. Patch to fix a spinlock lockup in the driver that sometimes happens when the tasklet starts. Signed-off-by: Claudio Scordino Signed-off-by: Dave Bender Tested-by: Dave Bender Acked-by: Nicolas Ferre Acked-by: Alan Cox Signed-off-by: Greg Kroah-Hartman

Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2011-11-22T04:36:46Z

* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: TTY: ldisc, wait for ldisc infinitely in hangup TTY: ldisc, move wait idle to caller TTY: ldisc, allow waiting for ldisc arbitrarily long Revert "tty/serial: Prevent drop of DCD on suspend for Tegra UARTs" RS485: fix inconsistencies in the meaning of some variables pch_uart: Fix DMA resource leak issue serial,mfd: Fix CMSPAR setup tty/serial: Prevent drop of DCD on suspend for Tegra UARTs pch_uart: Change company name OKI SEMICONDUCTOR to LAPIS Semiconductor pch_uart: Support new device LAPIS Semiconductor ML7831 IOH pch_uart: Fix hw-flow control issue tty: hvc_dcc: Fix duplicate character inputs jsm: Change maintainership