From patchwork Mon Feb 8 22:38:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sebastian Andrzej Siewior X-Patchwork-Id: 12076721 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C21E9C433DB for ; Mon, 8 Feb 2021 23:01:17 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6D7A464DE1 for ; Mon, 8 Feb 2021 23:01:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D7A464DE1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 850B46EA1C; Mon, 8 Feb 2021 23:01:10 +0000 (UTC) Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 92BCF6EA13 for ; Mon, 8 Feb 2021 22:38:22 +0000 (UTC) From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1612823899; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BvatIb+SuoAuL1N1yaJF6Fqf9sEJaUMKCM1rr5oWM0c=; b=HQ8/+BYas8HMUkPF27kztYqrFhdPsFIp69WWxyy/EEF0Ir4mMx5TNUNl8G8wjx968H0tWA fijZ9pRp9yy5V9jXhZWQWreUCfT4VvtdxXJocSAJAfbcnTEnXMbC9JijwK3xwNArT9da0b i2UhsAjxTMq5BlTbjlWVLsDU1x9n3FZRGzADq8hV1tP/mBQz4OmBfad+vXFf9kj1rgEbE8 a8qdJntipwhJnbJEeljHzFMKkgJyINRhS4I8h5SIrUv8Qf6tIC/OEZMZn49zJVbro20krO QQNdgJn/wCKA3HDM9WtcFZWi60bIhfiG/B88mUBeQ3fJ50/YUEjVUQ8gyfmTrw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1612823899; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BvatIb+SuoAuL1N1yaJF6Fqf9sEJaUMKCM1rr5oWM0c=; b=3qtO6vvCZk8yVT+UG/xPNQ/5g6dZnHinwVdniGk7VN9PvM6WrZAx5BTDtKsCc/h3rdpMLb QvvC58VbkmR+NmCA== To: linux-fbdev@vger.kernel.org Subject: [PATCH 1/3] video: omap: Remove in_interrupt() usage. Date: Mon, 8 Feb 2021 23:38:08 +0100 Message-Id: <20210208223810.388502-2-bigeasy@linutronix.de> In-Reply-To: <20210208223810.388502-1-bigeasy@linutronix.de> References: <20210208223810.388502-1-bigeasy@linutronix.de> MIME-Version: 1.0 X-Mailman-Approved-At: Mon, 08 Feb 2021 23:01:06 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Greg Kroah-Hartman , Sebastian Andrzej Siewior , Russell King , dri-devel@lists.freedesktop.org, "Ahmed S. Darwish" , Thomas Gleixner , linux-omap@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: "Ahmed S. Darwish" alloc_req() uses in_interrupt() to detect if it is safe to use down(). The usage of in_interrupt() in drivers is phased out and Linus clearly requested that code which changes behaviour depending on context should either be separated or the context be conveyed in an argument passed by the caller, which usually knows the context. The semaphore is used as a counting semaphore, initialized with the number of slots in the request pool minus IRQ_REQ_POOL_SIZE - which are reserved for the in_interrupt() user to ensure that a request is always available. The preemptible user will block on the semphore waiting for a request to become available in case there are no requests available. Replace in_interrupt() with a `can_sleep' argument to indicate if it is safe to block on the sempahore. Cc: linux-omap@vger.kernel.org Signed-off-by: Ahmed S. Darwish Signed-off-by: Sebastian Andrzej Siewior --- drivers/video/fbdev/omap/hwa742.c | 42 ++++++++++++++++++++----------- 1 file changed, 28 insertions(+), 14 deletions(-) diff --git a/drivers/video/fbdev/omap/hwa742.c b/drivers/video/fbdev/omap/hwa742.c index cfe63932f8255..b191bef22d984 100644 --- a/drivers/video/fbdev/omap/hwa742.c +++ b/drivers/video/fbdev/omap/hwa742.c @@ -100,6 +100,14 @@ struct { struct hwa742_request req_pool[REQ_POOL_SIZE]; struct list_head pending_req_list; struct list_head free_req_list; + + /* + * @req_lock: protect request slots pool and its tracking lists + * @req_sema: counter; slot allocators from task contexts must + * push it down before acquiring a slot. This + * guarantees that atomic contexts will always have + * a minimum of IRQ_REQ_POOL_SIZE slots available. + */ struct semaphore req_sema; spinlock_t req_lock; @@ -224,13 +232,13 @@ static void disable_tearsync(void) hwa742_write_reg(HWA742_NDP_CTRL, b); } -static inline struct hwa742_request *alloc_req(void) +static inline struct hwa742_request *alloc_req(bool can_sleep) { unsigned long flags; struct hwa742_request *req; int req_flags = 0; - if (!in_interrupt()) + if (can_sleep) down(&hwa742.req_sema); else req_flags = REQ_FROM_IRQ_POOL; @@ -399,8 +407,8 @@ static void send_frame_complete(void *data) hwa742.int_ctrl->enable_plane(OMAPFB_PLANE_GFX, 0); } -#define ADD_PREQ(_x, _y, _w, _h) do { \ - req = alloc_req(); \ +#define ADD_PREQ(_x, _y, _w, _h, can_sleep) do {\ + req = alloc_req(can_sleep); \ req->handler = send_frame_handler; \ req->complete = send_frame_complete; \ req->par.update.x = _x; \ @@ -413,7 +421,8 @@ static void send_frame_complete(void *data) } while(0) static void create_req_list(struct omapfb_update_window *win, - struct list_head *req_head) + struct list_head *req_head, + bool can_sleep) { struct hwa742_request *req; int x = win->x; @@ -427,7 +436,7 @@ static void create_req_list(struct omapfb_update_window *win, color_mode = win->format & OMAPFB_FORMAT_MASK; if (x & 1) { - ADD_PREQ(x, y, 1, height); + ADD_PREQ(x, y, 1, height, can_sleep); width--; x++; flags &= ~OMAPFB_FORMAT_FLAG_TEARSYNC; @@ -439,19 +448,19 @@ static void create_req_list(struct omapfb_update_window *win, if (xspan * height * 2 > hwa742.max_transmit_size) { yspan = hwa742.max_transmit_size / (xspan * 2); - ADD_PREQ(x, ystart, xspan, yspan); + ADD_PREQ(x, ystart, xspan, yspan, can_sleep); ystart += yspan; yspan = height - yspan; flags &= ~OMAPFB_FORMAT_FLAG_TEARSYNC; } - ADD_PREQ(x, ystart, xspan, yspan); + ADD_PREQ(x, ystart, xspan, yspan, can_sleep); x += xspan; width -= xspan; flags &= ~OMAPFB_FORMAT_FLAG_TEARSYNC; } if (width) - ADD_PREQ(x, y, 1, height); + ADD_PREQ(x, y, 1, height, can_sleep); } static void auto_update_complete(void *data) @@ -461,12 +470,12 @@ static void auto_update_complete(void *data) jiffies + HWA742_AUTO_UPDATE_TIME); } -static void hwa742_update_window_auto(struct timer_list *unused) +static void __hwa742_update_window_auto(bool can_sleep) { LIST_HEAD(req_list); struct hwa742_request *last; - create_req_list(&hwa742.auto_update_window, &req_list); + create_req_list(&hwa742.auto_update_window, &req_list, can_sleep); last = list_entry(req_list.prev, struct hwa742_request, entry); last->complete = auto_update_complete; @@ -475,6 +484,11 @@ static void hwa742_update_window_auto(struct timer_list *unused) submit_req_list(&req_list); } +static void hwa742_update_window_auto(struct timer_list *unused) +{ + __hwa742_update_window_auto(false); +} + int hwa742_update_window_async(struct fb_info *fbi, struct omapfb_update_window *win, void (*complete_callback)(void *arg), @@ -497,7 +511,7 @@ int hwa742_update_window_async(struct fb_info *fbi, goto out; } - create_req_list(win, &req_list); + create_req_list(win, &req_list, true); last = list_entry(req_list.prev, struct hwa742_request, entry); last->complete = complete_callback; @@ -544,7 +558,7 @@ static void hwa742_sync(void) struct hwa742_request *req; struct completion comp; - req = alloc_req(); + req = alloc_req(true); req->handler = sync_handler; req->complete = NULL; @@ -599,7 +613,7 @@ static int hwa742_set_update_mode(enum omapfb_update_mode mode) omapfb_notify_clients(hwa742.fbdev, OMAPFB_EVENT_READY); break; case OMAPFB_AUTO_UPDATE: - hwa742_update_window_auto(0); + __hwa742_update_window_auto(true); break; case OMAPFB_UPDATE_DISABLED: break;