- 26 Jul, 2013 34 commits
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Laurent Pinchart authored
Replace kzalloc and clk_get by their managed counterparts to simplify error and cleanup paths. Signed-off-by:
Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Andreas Platschek authored
-> The ledptrs[] array is never initialized. -> There is no place where kbd->ledmode is set to LED_SHOW_MEM therefore the if statement does not make much sense. -> Since LED_SHOW_MEM is not used, it can be removed from the header file as well. Signed-off-by:
Andreas Platschek <andi.platschek@gmail.com> Signed-off-by:
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Stephen Boyd authored
UARTDM cores have a TX fifo that can accept more than one character per register write, but the msm_serial driver currently only supports 1 character mode. Add support for this mode of operation to speed up the transmit path on DM devices. Signed-off-by:
Stephen Boyd <sboyd@codeaurora.org> Acked-by:
David Brown <davidb@codeaurora.org> Signed-off-by:
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Stephen Boyd authored
Currently msm_set_baud_rate() assumes the uart clock rate is 1.8432 MHz. This is not always true, and limits our options to program the baud rate. Instead of assuming the rate and hard-coding the baud_code based on it, calculate the divider that we want and try to find the closest baud_code that matches. This allows us to support uarts with faster clock speeds. Signed-off-by:
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Stephen Boyd authored
drivers/tty/serial/msm_serial.c:302:6: warning: symbol 'msm_set_mctrl' was not declared. Should it be static? drivers/tty/serial/msm_serial.c:597:17: warning: incorrect type in argument 2 (different address spaces) drivers/tty/serial/msm_serial.c:597:17: expected void volatile [noderef] <asn:2>*addr drivers/tty/serial/msm_serial.c:597:17: got unsigned int * drivers/tty/serial/msm_serial.c:608:33: warning: incorrect type in argument 1 (different address spaces) drivers/tty/serial/msm_serial.c:608:33: expected void volatile [noderef] <asn:2>*addr drivers/tty/serial/msm_serial.c:608:33: got unsigned int *gsbi_base drivers/tty/serial/msm_serial.c:648:37: warning: incorrect type in assignment (different address spaces) drivers/tty/serial/msm_serial.c:648:37: expected unsigned int *gsbi_base drivers/tty/serial/msm_serial.c:648:37: got void [noderef] <asn:2>* Mark the ioremapped memory as __iomem and use writel instead of iowrite because we're not dealing with PCI devices. Also, mark msm_set_mctrl() static because it isn't used outside this file. Signed-off-by:
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Stephen Boyd authored
UARTDM serial devices require us to wait for the entire TX fifo to drain before we can change the contents of the NCF_TX register. Furthermore, if we write any characters to the TX fifo within the same clock cycle of changing the NCF_TX register the NCF_TX register won't latch properly. To fix these issues we should read back the NCF_TX register to delay any TX fifo accesses by a clock cycle and we should wait for the TX fifo to drain (instead of just waiting for the fifo to be ready to receive more characters). Failure to do so leads to random NUL bytes interspersed in the output. Signed-off-by:
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Ian Abbott authored
These two defines are no longer used. They were only used by the PCI serial driver "8250_pci" to support the original ADDI-DATA APCI-7800 card. In that driver, PCI_VENDOR_ID_ADDIDATA_OLD has been replaced with PCI_VENDOR_ID_AMCC which has the same value (0x10e8), and PCI_DEVICE_ID_ADDIDATA_APCI7800 has been replaced with a local #define PCI_DEVICE_ID_AMCC_ADDIDATA_APCI7800 with the same value (0x818e). Signed-off-by:
Ian Abbott <abbotti@mev.co.uk> Acked-by:
Bjorn Helgaas <bhelgaas@google.com> Signed-off-by:
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Ian Abbott authored
The quirks and PCI ID table entries for the original ADDI-DATA APCI-7800 (not the newer APCI-7800-3) use PCI_DEVICE_ID_ADDIDATA_APCI7800 from <linux/pci_ids.h> but the device ID was actually assigned to ADDI-DATA by Applied Micro Circuits Corporation (PCI_VENDOR_ID_AMCC). Replace it locally with #define PCI_DEVICE_ID_AMCC_ADDIDATA_APCI7800. Signed-off-by:
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Ian Abbott authored
PCI_VENDOR_ID_ADDIDATA_OLD has the same value (0x10e8) as PCI_VENDOR_ID_AMCC in <linux/pci_ids.h>. The vender ID is actually assigned to Applied Micro Circuits Corporation. The 8250_pci driver uses PCI_VENDOR_ID_ADDIDATA_OLD in the lists of quirks and PCI IDs for the ADDI-DATA APCI-7800 card. Change it to use the more accurate PCI_VENDOR_ID_AMCC. Signed-off-by:
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Ian Abbott authored
PCI_VENDOR_ID_AMCC is defined locally in "drivers/staging/comedi/comedidev.h" for a few comedi hardware drivers, namely "adl_pci9118", "addi_apci_1500" and "addi_apci_3120" (also "addi_apci_1710" but that is not currently built and will probably be removed soon). Move the define into "include/linux/pci_ids.h" as it is shared by several drivers (albeit all comedi drivers currently). PCI_VENDOR_ID_AMCC happens to have the same value (0x10e8) as PCI_VENDOR_ID_ADDIDATA_OLD. The vendor ID is actually assigned to Applied Micro Circuits Corporation and Addi-Data were using device IDs assigned by AMCC on some of their earlier PCI boards. The PCI_VENDOR_ID_ADDIDATA_OLD define is still being used by the "8250_pci" PCI serial board driver. Signed-off-by:
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Srinivas Kandagatla authored
This patch adds support to ASC (asynchronous serial controller) driver, which is basically a standard serial driver. This IP is common across all the ST parts for settop box platforms. ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality. It support all industry standard baud rates. Signed-off-by:
Srinivas Kandagatla <srinivas.kandagatla@st.com> CC: Stephen Gallimore <stephen.gallimore@st.com> CC: Stuart Menefy <stuart.menefy@st.com> CC: Arnd Bergmann <arnd@arndb.de> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Uwe Kleine-König authored
Signed-off-by:
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:
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Uwe Kleine-König authored
The driver fails to build on x86 because writel_relaxed isn't available there. That function exists on arm, arm64, avr32, hexagon, mips and sh, but adding all these is overkill so stick to arm only. Signed-off-by:
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Wei Yongjun authored
Add the missing iounmap() before return from msm_request_port() in the error handling case. Signed-off-by:
Wei Yongjun <yongjun_wei@trendmicro.com.cn> Reviewed-by:
Ivan T. Ivanov <iivanov@mm-sol.com> Signed-off-by:
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Axel Lin authored
No idea why we have redundant testing for ifdef CONFIG_SERIAL_BFIN_MODULE, check it once is enough. Signed-off-by:
Axel Lin <axel.lin@ingics.com> Acked-by:
Sonic Zhang <sonic.zhang@analog.com> Signed-off-by:
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Darren Hart authored
Use the DMI interface rather than manually matching DMI strings. Signed-off-by:
Darren Hart <dvhart@linux.intel.com> Cc: Michael Brunner <mibru@gmx.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Kees Cook authored
Some serial ports will not use the standard base baud rate. Report this after initialization so it might be discovered and used for early console configuration. Signed-off-by:
Kees Cook <keescook@chromium.org> Signed-off-by:
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Grygorii Strashko authored
If earlyprintk is enabled and current UART is console port the platform code can mark it as RPM_ACTIVE to sync real IP state with PM Runtime and avoid resuming of already active device, but now, driver initialization will be performed in the wrong way: pm_runtime_enable(&pdev->dev); <-- PM runtime alowed (device state RPM_ACTIVE) if (omap_up_info->autosuspend_timeout == 0) omap_up_info->autosuspend_timeout = -1; device_init_wakeup(up->dev, true); pm_runtime_use_autosuspend(&pdev->dev); <-- update_autosuspend() will be called and it will disable device (device state RPM_SUSPENDED) pm_runtime_set_autosuspend_delay(&pdev->dev, omap_up_info->autosuspend_timeout); <-- update_autosuspend() will be called which will re-enable device (device state RPM_ACTIVE), because autosuspend_timeout < 0 pm_runtime_irq_safe(&pdev->dev); pm_runtime_get_sync(&pdev->dev); <-- will do nothing Such behavior isn't expected by OMAP serial drivers and causes unpredictable calls of serial_omap_runtime_suspend() and serial_omap_runtime_resume(). Hence, fix it by allowing PM runtime only after all its parameters are configured. CC: Tony Lindgren <tony@atomide.com> CC: Rajendra Nayak <rnayak@ti.com> CC: Felipe Balbi <balbi@ti.com> CC: Kevin Hilman <khilman@linaro.org> Tested-by:Mark Jackson <mpfj-list@newflow.co.uk> Signed-off-by:
Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by:
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Axel Lin authored
Signed-off-by:
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Shawn Guo authored
Function lpuart_setup_watermark() clears some bits in register UARTCR2 before writing FIFO configuration registers as required by hardware. But it should restore UARTCR2 after that. Otherwise, we end up changing UARTCR2 register when setting up watermark, and that is not really desirable. At least, when low-level debug and earlyprint is enabled, serial console is broken due to it. Fix the problem by restoring UARTCR2 register at the end of function lpuart_setup_watermark(). Signed-off-by:
Shawn Guo <shawn.guo@linaro.org> Signed-off-by:
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Ruchika Kharwar authored
Ensure the Interrupt handling routine return IRQ_HANDLED vs IRQ_NONE. Signed-off-by:
Ruchika Kharwar <ruchika@ti.com> Signed-off-by:
Alexander Savchenko <oleksandr.savchenko@ti.com> Signed-off-by:
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Vikram Pandita authored
Otherwise serial driver would crash accessing platform_data that was not initialized in functions like: serial_omap_pm(...) ... if (!state && pdata->enable_wakeup) ^^^^^^^ ... Signed-off-by:Vikram Pandita <vikram.pandita@ti.com> Signed-off-by:
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Ruchika Kharwar authored
The revision register is a 32 bit register. The serial_in() function reads only the lower 16 bits of the register. This leads to an incorrect computation of the Module revision. Signed-off-by:
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Dmitry Fink authored
Current logic results in interrupt storm since the fifo is constantly below the threshold level. Change the logic to fill all the available spaces in the fifo as long as we have data to minimize the possibilty of underflow and elimiate excessive interrupts. Signed-off-by:
Dmitry Fink <finik@ti.com> Signed-off-by:
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Govindraj.R authored
wer has TX wakeup bit available enable the same by populating the necessary tx wakeup flag for the applicable module ip blocks and use the same while configuaring wer reg. Also wer is not context restored, restore wer when context is lost. Cc: Paul Walmsley <paul@pwsan.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Kevin Hilman <kevin.hilman@linaro.org> Acked-by:
Govindraj.R <govindraj.raja@ti.com> Signed-off-by:
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Stefan Seyfried authored
The recent regression about NetMos 9835 Multi-I/O boards indicates that comment pointing to the parport_serial driver could be helpful. Signed-off-by:
Stefan Seyfried <seife+kernel@b1-systems.com> Signed-off-by:
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Alexander Shiyan authored
This patch adds support for MAX14830 (advanced quad universal asynchronous receiver-transmitter) into max310x driver. Signed-off-by:
Alexander Shiyan <shc_work@mail.ru> Signed-off-by:
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Alexander Shiyan authored
This patch adds support for MAX3109 (advanced dual universal asynchronous receiver-transmitter) into max310x driver. Signed-off-by:
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Alexander Shiyan authored
This patch rework max310x driver. Major changes have been made: - Prepare driver to support ICs with more than one UART. - Prepare driver to support work with I2C-bus. The patch changes almost every function and can not be divided into parts. Signed-off-by:
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Huang Shijie authored
We only enable the DMA support when the following are meet: [1] The uart port supports the hardware flow control(CTS/RTS). (Some uart port does not support the CTS/RTS.) [2] The application enables the CTS/RTS. [3] The Soc is imx6q. For the sdma's firmware limit, we do not support the DMA except the imx6q platform. [4] The uart is not used as a console. Signed-off-by:Huang Shijie <b32955@freescale.com> Signed-off-by:
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Hubert Feurstein authored
It was not possible to set custom-baudrates like 62500. Signed-off-by:
Hubert Feurstein <h.feurstein@gmail.com> Signed-off-by:
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Huang Shijie authored
We will add the DMA support for the imx uart. For the firmware's limit, only the imx6 serial chips (including the imx6q, imx6dl, imx6sl) can support the DMA. This patch adds the necessary macro and helper to distinguish the imx6q uart from the other imx uart. Other chips can use the "fsl,imx6q-uart" to enable the DMA support. This patch also replaces the check "is_imx21_uart()" with "!is_imx1_uart()". Signed-off-by:
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Huang Shijie authored
The uart_console() check makes the clocks(clk_per and clk_ipg) opened even when we close the console uart. This patch enable/disable the clocks in imx_console_write(), so we can keep the clocks closed when the console uart is closed. Also remove the clock enable/disable oprations in the probe, we do not need them any more. Signed-off-by:
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Jingoo Han authored
The driver core clears the driver data to NULL after device_release or on probe failure, since commit 0998d063 (device-core: Ensure drvdata = NULL when no driver is bound). Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by:
Jingoo Han <jg1.han@samsung.com> Acked-by:
Barry Song <baohua.song@csr.com> Acked-by:
Tony Prisk <linux@prisktech.co.nz> Acked-by:
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- 24 Jul, 2013 6 commits
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Hendrik Brueckner authored
Implement the dtr_rts() hvc console callback to improve control when to disconnect the IUCV connection. Previously, the IUCV connection was disconnected during the notifier_del() callback, i.e., when the last file descriptor to the hvc terminal device was closed. Recent changes in login programs caused undesired disconnects during the login phase. To prevent these kind of disconnects, implement the dtr_rts callback to implicitly handle the HUPCL termios control via the hvc_console driver. Signed-off-by:
Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by:
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Hendrik Brueckner authored
Introduce a new callback to explicitly handle the HUPCL termios control flag. This prepares for a follow-up commit for the hvc_iucv device driver to improve handling when to drop an established network connection. The callback naming is based on the recently added tty_port interface to facilitate a potential refactoring of the hvc_console to use tty_port functions. Signed-off-by:
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Wolfram Sang authored
Since commit ab78029e (drivers/pinctrl: grab default handles from device core), we can rely on device core for setting the default pins. Compile tested only. Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13) Signed-off-by:
Wolfram Sang <wsa@the-dreams.de> Acked-by:
Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by:
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Aldo Iljazi authored
Specifically: n_gsm.c:810: ERROR: space required before the open parenthesis '(' n_gsm.c:830: WARNING: line over 80 characters n_gsm.c:971: ERROR: trailing whitespace n_gsm.c:984: ERROR: code indent should use tabs where possible n_gsm.c:984: WARNING: please, no space before tabs n_gsm.c:984: WARNING: please, no spaces at the start of a line n_gsm.c:1141: WARNING: space prohibited before semicolon n_gsm.c:1743: ERROR: space required before the open brace '{' n_gsm.c:1744: WARNING: line over 80 characters n_gsm.c:1745: ERROR: code indent should use tabs where possible n_gsm.c:1746: ERROR: code indent should use tabs where possible n_gsm.c:2908: WARNING: line over 80 characters n_gsm.c:2912: ERROR: trailing whitespace Signed-off-by:Aldo Iljazi <neonsync1@gmail.com> Signed-off-by:
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Peter Hurley authored
Commits 6a1c0680 and 9356b535, respectively 'tty: Convert termios_mutex to termios_rwsem' and 'n_tty: Access termios values safely' introduced a circular lock dependency with console_lock and termios_rwsem. The lockdep report [1] shows that n_tty_write() will attempt to claim console_lock while holding the termios_rwsem, whereas tty_do_resize() may already hold the console_lock while claiming the termios_rwsem. Since n_tty_write() and tty_do_resize() do not contend over the same data -- the tty->winsize structure -- correct the lock dependency by introducing a new lock which specifically serializes access to tty->winsize only. [1] Lockdep report ====================================================== [ INFO: possible circular locking dependency detected ] 3.10.0-0+tip-xeon+lockdep #0+tip Not tainted ------------------------------------------------------- modprobe/277 is trying to acquire lock: (&tty->termios_rwsem){++++..}, at: [<ffffffff81452656>] tty_do_resize+0x36/0xe0 but task is already holding lock: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((fb_notifier_list).rwsem){.+.+.+}: [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff8175b797>] down_read+0x47/0x5c [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b -> #1 (console_lock){+.+.+.}: [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff810430a7>] console_lock+0x77/0x80 [<ffffffff8146b2a1>] con_flush_chars+0x31/0x50 [<ffffffff8145780c>] n_tty_write+0x1ec/0x4d0 [<ffffffff814541b9>] tty_write+0x159/0x2e0 [<ffffffff814543f5>] redirected_tty_write+0xb5/0xc0 [<ffffffff811ab9d5>] vfs_write+0xc5/0x1f0 [<ffffffff811abec5>] SyS_write+0x55/0xa0 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b -> #0 (&tty->termios_rwsem){++++..}: [<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30 [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff8175b724>] down_write+0x44/0x70 [<ffffffff81452656>] tty_do_resize+0x36/0xe0 [<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0 [<ffffffff8146c99f>] vc_resize+0x1f/0x30 [<ffffffff813e4535>] fbcon_init+0x385/0x5a0 [<ffffffff8146a4bc>] visual_init+0xbc/0x120 [<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320 [<ffffffff8146cfa1>] do_take_over_console+0x61/0x70 [<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0 [<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820 [<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110 [<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b other info that might help us debug this: Chain exists of: &tty->termios_rwsem --> console_lock --> (fb_notifier_list).rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((fb_notifier_list).rwsem); lock(console_lock); lock((fb_notifier_list).rwsem); lock(&tty->termios_rwsem); *** DEADLOCK *** 7 locks held by modprobe/277: #0: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b5b>] __driver_attach+0x5b/0xb0 #1: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b69>] __driver_attach+0x69/0xb0 #2: (drm_global_mutex){+.+.+.}, at: [<ffffffffa008a6dd>] drm_get_pci_dev+0xbd/0x2a0 [drm] #3: (registration_lock){+.+.+.}, at: [<ffffffff813d93f5>] register_framebuffer+0x25/0x320 #4: (&fb_info->lock){+.+.+.}, at: [<ffffffff813d8116>] lock_fb_info+0x26/0x60 #5: (console_lock){+.+.+.}, at: [<ffffffff813d95a4>] register_framebuffer+0x1d4/0x320 #6: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0 stack backtrace: CPU: 0 PID: 277 Comm: modprobe Not tainted 3.10.0-0+tip-xeon+lockdep #0+tip Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012 ffffffff8213e5e0 ffff8802aa2fb298 ffffffff81755f19 ffff8802aa2fb2e8 ffffffff8174f506 ffff8802aa2fa000 ffff8802aa2fb378 ffff8802aa2ea8e8 ffff8802aa2ea910 ffff8802aa2ea8e8 0000000000000006 0000000000000007 Call Trace: [<ffffffff81755f19>] dump_stack+0x19/0x1b [<ffffffff8174f506>] print_circular_bug+0x1fb/0x20c [<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30 [<ffffffff810b775e>] ? mark_held_locks+0xae/0x120 [<ffffffff810b78d5>] ? trace_hardirqs_on_caller+0x105/0x1d0 [<ffffffff810b6d62>] lock_acquire+0x92/0x1f0 [<ffffffff81452656>] ? tty_do_resize+0x36/0xe0 [<ffffffff8175b724>] down_write+0x44/0x70 [<ffffffff81452656>] ? tty_do_resize+0x36/0xe0 [<ffffffff81452656>] tty_do_resize+0x36/0xe0 [<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0 [<ffffffff8146c99f>] vc_resize+0x1f/0x30 [<ffffffff813e4535>] fbcon_init+0x385/0x5a0 [<ffffffff8146a4bc>] visual_init+0xbc/0x120 [<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320 [<ffffffff8146cfa1>] do_take_over_console+0x61/0x70 [<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0 [<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820 [<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110 [<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0 [<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20 [<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320 [<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper] [<ffffffff8173cbcb>] ? kmemleak_alloc+0x5b/0xc0 [<ffffffff81198874>] ? kmem_cache_alloc_trace+0x104/0x290 [<ffffffffa01035e1>] ? drm_fb_helper_single_add_all_connectors+0x81/0xf0 [drm_kms_helper] [<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau] [<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau] [<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm] [<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau] [<ffffffff8175f162>] ? _raw_spin_unlock_irqrestore+0x42/0x80 [<ffffffff813b13db>] local_pci_probe+0x4b/0x80 [<ffffffff813b1701>] pci_device_probe+0x111/0x120 [<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0 [<ffffffff81497bab>] __driver_attach+0xab/0xb0 [<ffffffff81497b00>] ? driver_probe_device+0x3a0/0x3a0 [<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0 [<ffffffff814971fe>] driver_attach+0x1e/0x20 [<ffffffff81496cc1>] bus_add_driver+0x111/0x290 [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffff814982b7>] driver_register+0x77/0x170 [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffff813b0454>] __pci_register_driver+0x64/0x70 [<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm] [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffffa022a000>] ? 0xffffffffa0229fff [<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau] [<ffffffff810002ea>] do_one_initcall+0xea/0x1a0 [<ffffffff810c54cb>] load_module+0x123b/0x1bf0 [<ffffffff81399a50>] ? ddebug_proc_open+0xb0/0xb0 [<ffffffff813855ae>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff810c5f57>] SyS_init_module+0xd7/0x120 [<ffffffff817677c2>] system_call_fastpath+0x16/0x1b Signed-off-by:
Peter Hurley <peter@hurleysoftware.com> Signed-off-by:
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Peter Hurley authored
Acquiring the write_wait queue spin lock now accounts for the largest slice of cpu time on the tty write path. Two factors contribute to this situation; a overly-pessimistic line discipline write loop which _always_ sets up a wait loop even if i/o will immediately succeed, and on ptys, a wakeup storm from reads and writes. Writer wakeup does not need to be performed by the pty driver. Firstly, since the actual i/o is performed within the write, the line discipline write loop will continue while space remains in the flip buffers. Secondly, when space becomes avail in the line discipline receive buffer (and thus also in the flip buffers), the pty unthrottle re-wakes the writer (non-flow-controlled line disciplines unconditionally unthrottle the driver when data is received). Thus, existing in-kernel i/o is guaranteed to advance. Finally, writer wakeup occurs at the conclusion of the line discipline write (in tty_write_unlock()). This guarantees that any user-space write waiters are woken to continue additional i/o. Signed-off-by:
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