From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752549Ab2LEA7N (ORCPT ); Tue, 4 Dec 2012 19:59:13 -0500 Received: from mailout4.samsung.com ([203.254.224.34]:13401 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752152Ab2LEA7K (ORCPT ); Tue, 4 Dec 2012 19:59:10 -0500 X-AuditID: cbfee61a-b7fa66d0000004cf-b6-50be9c5c473e From: Jingoo Han To: "'Andrew Morton'" , "'LKML'" Cc: "'Marko Katic'" , "'Grant Likely'" , "'Florian Tobias Schandinat'" , "'Richard Purdie'" , linux-arm-kernel@lists.infradead.org, "'Jingoo Han'" Subject: [PATCH v4] backlight: corgi_lcd: Use gpio_set_value_cansleep() to avoid WARN_ON Date: Wed, 05 Dec 2012 09:59:07 +0900 Message-id: <000201cdd283$baf50160$30df0420$%han@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-index: Ac3Sg7qDkEV3VJbdT9OePeZe/2bfkw== Content-language: ko DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrPIsWRmVeSWpSXmKPExsVy+t8zY92YOfsCDI4s07S4vGsOmwOjx+dN cgGMUVw2Kak5mWWpRfp2CVwZm+/qFWxVrmi//46tgXGtfBcjJ4eEgInEgmVPGSFsMYkL99az dTFycQgJLGOUOHX4HSNM0bxJXYwQiemMEuuffoFyZjNJrPpygxmkik1ATeLLl8PsILaIQIRE 84xZzCBFzAKNTBKvF8xjBUkIC0RJvHp4AWwsi4CqxKqjh8BsXgFbiefz7zFB2IISPybfYwGx mQW0JDZva2KFsOUlNq95CzSUA+gkdYlHf3UhdulJHL32kA2iRERi34t3UOMFJL5NPsQCUS4r sekA2DkSAu3sEhPPLoH6TFLi4IobLBMYxWYh2TwLyeZZSDbPQrJiASPLKkbR1ILkguKk9FxD veLE3OLSvHS95PzcTYyQWJHawbiyweIQowAHoxIPb5bevgAh1sSy4srcQ4wSHMxKIrz/7IBC vCmJlVWpRfnxRaU5qcWHGH2ALp/ILCWanA+M47ySeENjYxMzE1MTc0tTc1McwkrivM0eKQFC AumJJanZqakFqUUw45g4OKUaGINVYvWdrCuUzsy7ubpI4njfqwCVG2LrWPqL/v78srf5YmmK UtqusHWCAb09SdN/pbW45TG0xTyYZtibIvVkgtiVmFdrtCbXlgrqJcz6tm/SyhvbcxqnCVhs Xb7B37dS5UxR8tFWpU/yqq5PxeN4XLNSvJ0OqzT3sG2ftSSzcsqpzmOS/63XKbEUZyQaajEX FScCAMcoqpfCAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrHIsWRmVeSWpSXmKPExsVy+t9jQd2YOfsCDHa1K1lc3jWHzYHR4/Mm uQDGqAZGm4zUxJTUIoXUvOT8lMy8dFsl7+B453hTMwNDXUNLC3MlhbzE3FRbJRefAF23zByg qUoKZYk5pUChgMTiYiV9O0wTQkPcdC1gGiN0fUOC4HqMDNBAwjrGjM139Qq2Kle033/H1sC4 Vr6LkZNDQsBEYt6kLkYIW0ziwr31bF2MXBxCAtMZJdY//cII4cxmklj15QYzSBWbgJrEly+H 2UFsEYEIieYZs5hBipgFGpkkXi+YxwqSEBaIknj18ALYWBYBVYlVRw+B2bwCthLP599jgrAF JX5MvscCYjMLaEls3tbECmHLS2xe8xZoKAfQSeoSj/7qQuzSkzh67SEbRImIxL4X7xgnMArM QjJpFpJJs5BMmoWkZQEjyypG0dSC5ILipPRcQ73ixNzi0rx0veT83E2M4Eh8JrWDcWWDxSFG AQ5GJR7eLL19AUKsiWXFlbmHGCU4mJVEeP/ZAYV4UxIrq1KL8uOLSnNSiw8x+gA9OpFZSjQ5 H5gk8kriDY1NzIwsjcwsjEzMzXEIK4nzNnukBAgJpCeWpGanphakFsGMY+LglGpgjN304tmN g6zc6S/r1uvsqewRKPLY3jq52EpiV9Kx+jOb6sUmZ7eZ7LXfVis2WWtt5m77qaGiMSWX1Tma FppI3w7ncuReyiezRKDITP2Dx6ZU67ttE/fXyVZkFi20X/q1ZTpD2jTfc2bn7DVeF6l5q23R OnqbvfDGIZs/3Da6xeyeptd9LjgpsRRnJBpqMRcVJwIApbSchPECAAA= X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marko Katic Changing backlight intensity on an Akita (Sharp Zaurus C-1000) triggers WARN_ON message: WARNING: at drivers/gpio/gpiolib.c:1672 __gpio_set_value+0x38/0xa4() Modules linked in: Backtrace: [] (dump_backtrace+0x0/0x110) from [] (dump_stack+0x18/0x1c) r6:c0158fc8 r5:00000009 r4:00000000 r3:c03d4f70 [] (dump_stack+0x0/0x1c) from [] (warn_slowpath_common+0x54/0x6c) [] (warn_slowpath_common+0x0/0x6c) from [] (warn_slowpath_null+0x24/0x2c) r8:c38d5c00 r7:c03f82c0 r6:00000000 r5:000000d0 r4:c384e4fc r3:00000009 [] (warn_slowpath_null+0x0/0x2c) from [] (__gpio_set_value+0x38/0xa4) [] (__gpio_set_value+0x0/0xa4) from [] (corgi_bl_set_intensity+0x44/0x74) r7:c3933418 r6:c3933400 r5:c392cdf0 r4:0000002f [] (corgi_bl_set_intensity+0x0/0x74) from [] (corgi_bl_update_status+0x5c/0x64) r5:c03d31f0 r4:c3933400 [] (corgi_bl_update_status+0x0/0x64) from [] (corgi_lcd_probe+0x1a8/0x258) r4:c392cdf0 r3:c0169bc0 [] (corgi_lcd_probe+0x0/0x258) from [] (spi_drv_probe+0x20/0x24) r8:00000052 r7:c0192d9c r6:c03da6e8 r5:c38d5c34 r4:c38d5c00 [] (spi_drv_probe+0x0/0x24) from [] (driver_probe_device+0xb0/0x208) [] (driver_probe_device+0x0/0x208) from [] (__driver_attach+0x70/0x94) r6:c03da6e8 r5:c38d5c34 r4:c38d5c00 r3:00000000 [] (__driver_attach+0x0/0x94) from [] (bus_for_each_dev+0x54/0x90) r6:c03da6e8 r5:c3827e80 r4:00000000 r3:00000000 [] (bus_for_each_dev+0x0/0x90) from [] (driver_attach+0x20/0x28) r7:00000000 r6:c03e29ec r5:c3932980 r4:c03da6e8 [] (driver_attach+0x0/0x28) from [] (bus_add_driver+0xd4/0x22c) [] (bus_add_driver+0x0/0x22c) from [] (driver_register+0xa4/0x134) r8:00000052 r7:c03ea900 r6:c03c32ac r5:c03bdfc8 r4:c03da6e8 [] (driver_register+0x0/0x134) from [] (spi_register_driver+0x4c/0x60) [] (spi_register_driver+0x0/0x60) from [] (corgi_lcd_driver_init+0x14/0x1c) [] (corgi_lcd_driver_init+0x0/0x1c) from [] (do_one_initcall+0x9c/0x174) [] (do_one_initcall+0x0/0x174) from [] (kernel_init+0xf4/0x2a8) [] (kernel_init+0x0/0x2a8) from [] (ret_from_fork+0x14/0x24) ---[ end trace a863a63f242ee38c ]--- Akita machines have backlight controls hooked to a gpio expander chip, max7310 using i2c transfers which can sleep. In this case, pca953x_gpio_set_value() can be called to control gpio, and pca953x_setup_gpio() sets can_sleep flag. Therefore, gpio_set_value_cansleep() should be used in order to avoid WARN_ON on akita machines. Akita is the only exception in this case since other users of corgi_lcd access backlight gpio controls through a different gpio expander which does not set the can_sleep flag. [jg1.han@samsung.com: used gpio_cansleep()] Signed-off-by: Marko Katic Signed-off-by: Jingoo Han --- Change since v3: - remove redundant wording from commit message Change since v2: - use gpio_cansleep() drivers/video/backlight/corgi_lcd.c | 17 +++++++++++++---- 1 files changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/video/backlight/corgi_lcd.c b/drivers/video/backlight/corgi_lcd.c index e2e1b62..e5168f4 100644 --- a/drivers/video/backlight/corgi_lcd.c +++ b/drivers/video/backlight/corgi_lcd.c @@ -408,11 +408,20 @@ static int corgi_bl_set_intensity(struct corgi_lcd *lcd, int intensity) /* Bit 5 via GPIO_BACKLIGHT_CONT */ cont = !!(intensity & 0x20) ^ lcd->gpio_backlight_cont_inverted; - if (gpio_is_valid(lcd->gpio_backlight_cont)) - gpio_set_value(lcd->gpio_backlight_cont, cont); + if (gpio_is_valid(lcd->gpio_backlight_cont)) { + if (gpio_cansleep(lcd->gpio_backlight_cont)) + gpio_set_value_cansleep(lcd->gpio_backlight_cont, cont); + else + gpio_set_value(lcd->gpio_backlight_cont, cont); + } - if (gpio_is_valid(lcd->gpio_backlight_on)) - gpio_set_value(lcd->gpio_backlight_on, intensity); + if (gpio_is_valid(lcd->gpio_backlight_on)) { + if (gpio_cansleep(lcd->gpio_backlight_on)) + gpio_set_value_cansleep(lcd->gpio_backlight_on, + intensity); + else + gpio_set_value(lcd->gpio_backlight_on, intensity); + } if (lcd->kick_battery) lcd->kick_battery(); -- 1.7.2.5