Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933225AbbGSTWS (ORCPT ); Sun, 19 Jul 2015 15:22:18 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:38797 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932957AbbGSTSg (ORCPT ); Sun, 19 Jul 2015 15:18:36 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Chen , Liu Ying , Tomi Valkeinen Subject: [PATCH 4.0 50/58] video: mxsfb: Make sure axi clock is enabled when accessing registers Date: Sun, 19 Jul 2015 12:11:28 -0700 Message-Id: <20150719190812.904230364@linuxfoundation.org> X-Mailer: git-send-email 2.4.6 In-Reply-To: <20150719190811.308546345@linuxfoundation.org> References: <20150719190811.308546345@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6448 Lines: 222 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Liu Ying commit 2fa3b4c4a78a5db3502ab9e32630ea660ff923d0 upstream. The LCDIF engines embedded in i.MX6sl and i.MX6sx SoCs need the axi clock as the engine's system clock. The clock should be enabled when accessing LCDIF registers, otherwise the kernel would hang up. We should also keep the clock enabled when the engine is being active to scan out frames from memory. This patch makes sure the axi clock is enabled when accessing registers so that the kernel hang up issue can be fixed. Reported-by: Peter Chen Tested-by: Peter Chen Signed-off-by: Liu Ying Signed-off-by: Tomi Valkeinen Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/mxsfb.c | 68 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 54 insertions(+), 14 deletions(-) --- a/drivers/video/fbdev/mxsfb.c +++ b/drivers/video/fbdev/mxsfb.c @@ -316,6 +316,18 @@ static int mxsfb_check_var(struct fb_var return 0; } +static inline void mxsfb_enable_axi_clk(struct mxsfb_info *host) +{ + if (host->clk_axi) + clk_prepare_enable(host->clk_axi); +} + +static inline void mxsfb_disable_axi_clk(struct mxsfb_info *host) +{ + if (host->clk_axi) + clk_disable_unprepare(host->clk_axi); +} + static void mxsfb_enable_controller(struct fb_info *fb_info) { struct mxsfb_info *host = to_imxfb_host(fb_info); @@ -333,14 +345,13 @@ static void mxsfb_enable_controller(stru } } - if (host->clk_axi) - clk_prepare_enable(host->clk_axi); - if (host->clk_disp_axi) clk_prepare_enable(host->clk_disp_axi); clk_prepare_enable(host->clk); clk_set_rate(host->clk, PICOS2KHZ(fb_info->var.pixclock) * 1000U); + mxsfb_enable_axi_clk(host); + /* if it was disabled, re-enable the mode again */ writel(CTRL_DOTCLK_MODE, host->base + LCDC_CTRL + REG_SET); @@ -380,11 +391,11 @@ static void mxsfb_disable_controller(str reg = readl(host->base + LCDC_VDCTRL4); writel(reg & ~VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4); + mxsfb_disable_axi_clk(host); + clk_disable_unprepare(host->clk); if (host->clk_disp_axi) clk_disable_unprepare(host->clk_disp_axi); - if (host->clk_axi) - clk_disable_unprepare(host->clk_axi); host->enabled = 0; @@ -421,6 +432,8 @@ static int mxsfb_set_par(struct fb_info mxsfb_disable_controller(fb_info); } + mxsfb_enable_axi_clk(host); + /* clear the FIFOs */ writel(CTRL1_FIFO_CLEAR, host->base + LCDC_CTRL1 + REG_SET); @@ -438,6 +451,7 @@ static int mxsfb_set_par(struct fb_info ctrl |= CTRL_SET_WORD_LENGTH(3); switch (host->ld_intf_width) { case STMLCDIF_8BIT: + mxsfb_disable_axi_clk(host); dev_err(&host->pdev->dev, "Unsupported LCD bus width mapping\n"); return -EINVAL; @@ -451,6 +465,7 @@ static int mxsfb_set_par(struct fb_info writel(CTRL1_SET_BYTE_PACKAGING(0x7), host->base + LCDC_CTRL1); break; default: + mxsfb_disable_axi_clk(host); dev_err(&host->pdev->dev, "Unhandled color depth of %u\n", fb_info->var.bits_per_pixel); return -EINVAL; @@ -504,6 +519,8 @@ static int mxsfb_set_par(struct fb_info fb_info->fix.line_length * fb_info->var.yoffset, host->base + host->devdata->next_buf); + mxsfb_disable_axi_clk(host); + if (reenable) mxsfb_enable_controller(fb_info); @@ -582,10 +599,14 @@ static int mxsfb_pan_display(struct fb_v offset = fb_info->fix.line_length * var->yoffset; + mxsfb_enable_axi_clk(host); + /* update on next VSYNC */ writel(fb_info->fix.smem_start + offset, host->base + host->devdata->next_buf); + mxsfb_disable_axi_clk(host); + return 0; } @@ -608,13 +629,17 @@ static int mxsfb_restore_mode(struct mxs unsigned line_count; unsigned period; unsigned long pa, fbsize; - int bits_per_pixel, ofs; + int bits_per_pixel, ofs, ret = 0; u32 transfer_count, vdctrl0, vdctrl2, vdctrl3, vdctrl4, ctrl; + mxsfb_enable_axi_clk(host); + /* Only restore the mode when the controller is running */ ctrl = readl(host->base + LCDC_CTRL); - if (!(ctrl & CTRL_RUN)) - return -EINVAL; + if (!(ctrl & CTRL_RUN)) { + ret = -EINVAL; + goto err; + } vdctrl0 = readl(host->base + LCDC_VDCTRL0); vdctrl2 = readl(host->base + LCDC_VDCTRL2); @@ -635,7 +660,8 @@ static int mxsfb_restore_mode(struct mxs break; case 1: default: - return -EINVAL; + ret = -EINVAL; + goto err; } fb_info->var.bits_per_pixel = bits_per_pixel; @@ -673,10 +699,14 @@ static int mxsfb_restore_mode(struct mxs pa = readl(host->base + host->devdata->cur_buf); fbsize = fb_info->fix.line_length * vmode->yres; - if (pa < fb_info->fix.smem_start) - return -EINVAL; - if (pa + fbsize > fb_info->fix.smem_start + fb_info->fix.smem_len) - return -EINVAL; + if (pa < fb_info->fix.smem_start) { + ret = -EINVAL; + goto err; + } + if (pa + fbsize > fb_info->fix.smem_start + fb_info->fix.smem_len) { + ret = -EINVAL; + goto err; + } ofs = pa - fb_info->fix.smem_start; if (ofs) { memmove(fb_info->screen_base, fb_info->screen_base + ofs, fbsize); @@ -689,7 +719,11 @@ static int mxsfb_restore_mode(struct mxs clk_prepare_enable(host->clk); host->enabled = 1; - return 0; +err: + if (ret) + mxsfb_disable_axi_clk(host); + + return ret; } static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host, @@ -915,7 +949,9 @@ static int mxsfb_probe(struct platform_d } if (!host->enabled) { + mxsfb_enable_axi_clk(host); writel(0, host->base + LCDC_CTRL); + mxsfb_disable_axi_clk(host); mxsfb_set_par(fb_info); mxsfb_enable_controller(fb_info); } @@ -954,11 +990,15 @@ static void mxsfb_shutdown(struct platfo struct fb_info *fb_info = platform_get_drvdata(pdev); struct mxsfb_info *host = to_imxfb_host(fb_info); + mxsfb_enable_axi_clk(host); + /* * Force stop the LCD controller as keeping it running during reboot * might interfere with the BootROM's boot mode pads sampling. */ writel(CTRL_RUN, host->base + LCDC_CTRL + REG_CLR); + + mxsfb_disable_axi_clk(host); } static struct platform_driver mxsfb_driver = { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/