9bcd04bfbb
We probably don't want to change I2C frequency while a transfer is in progress. The current implementation grabs a spinlock, but that only protected the writes to IICCON when starting a message, it didn't protect against clock changes in the middle of a transaction. Note: The i2c-core already grabs the adapter lock before calling s3c24xx_i2c_doxfer(), which ensures that only one caller is issuing a xfer at a time. This means it is not necessary to disable interrupts (spin_lock_irqsave) when changing frequencies, since there won't be any i2c interrupts if there is no on-going xfer. Lastly, i2c_lock_adapter() may cause the cpufreq_transition to sleep if if a xfer is in progress, but this is ok since cpufreq notifiers are called in a kernel thread, and there are already cases where it could sleep, such as when using i2c to update the output of a voltage regulator. Note: the cpufreq part of this change has no functional affect on exynos, where the i2c clock is independent of the cpufreq. But, there is a slight perfomance boost since we no longer need to lock/unlock an additional spinlock. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> |
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| accessibility | ||
| acpi | ||
| amba | ||
| ata | ||
| atm | ||
| auxdisplay | ||
| base | ||
| bcma | ||
| block | ||
| bluetooth | ||
| bus | ||
| cdrom | ||
| char | ||
| clk | ||
| clocksource | ||
| connector | ||
| cpufreq | ||
| cpuidle | ||
| crypto | ||
| dca | ||
| devfreq | ||
| dio | ||
| dma | ||
| edac | ||
| eisa | ||
| extcon | ||
| firewire | ||
| firmware | ||
| gpio | ||
| gpu | ||
| hid | ||
| hsi | ||
| hv | ||
| hwmon | ||
| hwspinlock | ||
| i2c | ||
| ide | ||
| idle | ||
| iio | ||
| infiniband | ||
| input | ||
| iommu | ||
| irqchip | ||
| isdn | ||
| leds | ||
| lguest | ||
| macintosh | ||
| md | ||
| media | ||
| memory | ||
| memstick | ||
| message | ||
| mfd | ||
| misc | ||
| mmc | ||
| mtd | ||
| net | ||
| nfc | ||
| nubus | ||
| of | ||
| oprofile | ||
| parisc | ||
| parport | ||
| pci | ||
| pcmcia | ||
| pinctrl | ||
| platform | ||
| pnp | ||
| power | ||
| pps | ||
| ps3 | ||
| ptp | ||
| pwm | ||
| rapidio | ||
| regulator | ||
| remoteproc | ||
| rpmsg | ||
| rtc | ||
| s390 | ||
| sbus | ||
| scsi | ||
| sfi | ||
| sh | ||
| sn | ||
| spi | ||
| ssb | ||
| staging | ||
| target | ||
| tc | ||
| thermal | ||
| tty | ||
| uio | ||
| usb | ||
| uwb | ||
| vfio | ||
| vhost | ||
| video | ||
| virt | ||
| virtio | ||
| vlynq | ||
| vme | ||
| w1 | ||
| watchdog | ||
| xen | ||
| zorro | ||
| Kconfig | ||
| Makefile | ||