From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751704Ab2LDF2U (ORCPT ); Tue, 4 Dec 2012 00:28:20 -0500 Received: from mailout1.samsung.com ([203.254.224.24]:11851 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753Ab2LDF2S (ORCPT ); Tue, 4 Dec 2012 00:28:18 -0500 X-AuditID: cbfee61b-b7f616d00000319b-b7-50bd89f06fb4 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 v3] backlight: corgi_lcd: Use gpio_set_value_cansleep() to avoid WARN_ON Date: Tue, 04 Dec 2012 14:28:15 +0900 Message-id: <000b01cdd1e0$293f0d90$7bbd28b0$%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: Ac3R4CjcxjabLco0SliKJ0TfRLMaJg== Content-language: ko DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrAIsWRmVeSWpSXmKPExsVy+t8zfd0PnXsDDNr7eC0u75rD5sDo8XmT XABjFJdNSmpOZllqkb5dAlfGgbUTmQs2KVV8+zWHtYHxqFwXIyeHhICJxLKNJ5ghbDGJC/fW s3UxcnEICSxjlPj25jEjTNHD3oUsEIlFjBKXfhxmgnBmM0ns/LUVrIpNQE3iy5fD7CC2iECE RPOMWcwgRcwCjUwSrxfMYwVJCAtESbyYuJoNxGYRUJXo37YCrJlXwFZi+5w77BC2oMSPyfdY QGxmAS2J9TuPM0HY8hKb17wFGsoBdJK6xKO/uhC79CTeboS4lFlARGLfi3eMEOMFJL5NPsQC US4rsekA2DkSAt3sEoumHGGF+ExS4uCKGywTGMVmIdk8C8nmWUg2z0KyYgEjyypG0dSC5ILi pPRcI73ixNzi0rx0veT83E2MkGiR3sG4qsHiEKMAB6MSD++CF3sChFgTy4orcw8xSnAwK4nw nvHaGyDEm5JYWZValB9fVJqTWnyI0Qfo8onMUqLJ+cBIziuJNzQ2NjEzMTUxtzQ1N8UhrCTO 2+yREiAkkJ5YkpqdmlqQWgQzjomDU6qBkS2Wna36uKOdWanikmzVxR0x2jlZr0uap6kJ3eHo frJMa+fE2rO3rd7y/f6iMWsLo8WU3lfhkv7s76VW37t9ount4prVbU8VBHXU6zVz5/QtcQx6 dpeR61Jzwi49Q0U+PkPOI3PXJ/l9OBXIY/LWuuRsCVPOfA7rluST1jW7u/7zOnq3ffNSYinO SDTUYi4qTgQAWu6o0MMCAAA= X-Brightmail-Tracker: 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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. 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 such as max7310 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 --- 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