From patchwork Wed Jan 27 17:29:01 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: 372960 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham 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 9284FC433E9 for ; Wed, 27 Jan 2021 17:31:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5CF5664DA6 for ; Wed, 27 Jan 2021 17:31:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343617AbhA0Rau (ORCPT ); Wed, 27 Jan 2021 12:30:50 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:57758 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235987AbhA0RaA (ORCPT ); Wed, 27 Jan 2021 12:30:00 -0500 From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1611768552; 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=YEjZOp8GCAMOFRDg3oxg2+c+yhJVKyviPPXBu30pB3M=; b=x5DdagCitRCeNaECo9vEZ9pJbd1M0ZplYkKkAjc8QW0CHzjVY7UWUUicofqsOid5Q7EPBU h6UT8880uQCZFqfYEJQsT0ljopcnGmn+KNzDk7YxD+tWFcvpGY4FVYEfwfLf9icLAHiJj6 0KaYwOrBhnYF0TdK4ot5QKMODZpZLxxkphf+IBHYoy6ycoEHMkghsnNlrDRDsl+kjM3uTN 8UzABcKxFOHEZFXeu+qtQpIJ4MfZ5Au6yF+K1btEPulpXgMp0zpzDMcvZosIMqmXIT2jJ3 WKOIKNYqx22zlk+sNSkkIh36y9GV2DOdTZOqw89eb25B39LaAnN3zaG0Dp4xJg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1611768552; 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=YEjZOp8GCAMOFRDg3oxg2+c+yhJVKyviPPXBu30pB3M=; b=3mHHww0ekTNZQhFmyUrOo+BHpk3ndmBHPbOOrpIKC+nD/NGyK6GFpxA4OWYmPpIqhrQC3I 7Z2gFMbob2t1HdDw== To: linux-omap@vger.kernel.org Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Thomas Gleixner , "Ahmed S. Darwish" , Sebastian Andrzej Siewior Subject: [PATCH 1/2] video: omap: Remove in_interrupt() usage. Date: Wed, 27 Jan 2021 18:29:01 +0100 Message-Id: <20210127172902.145335-2-bigeasy@linutronix.de> In-Reply-To: <20210127172902.145335-1-bigeasy@linutronix.de> References: <20210127172902.145335-1-bigeasy@linutronix.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org 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. 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; From patchwork Wed Jan 27 17:29:02 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: 372959 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, 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 D007DC433E0 for ; Wed, 27 Jan 2021 17:32:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86FAA60187 for ; Wed, 27 Jan 2021 17:32:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235425AbhA0RcB (ORCPT ); Wed, 27 Jan 2021 12:32:01 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:57766 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235996AbhA0RaB (ORCPT ); Wed, 27 Jan 2021 12:30:01 -0500 From: Sebastian Andrzej Siewior DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1611768553; 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=gV4s82FEuVJugdNoRBb0xE+COjn/uKSW2UKMDbD6jHQ=; b=wuR6CRkyif58OjIS/1cWiPhdkXgbh0OqmSlzr7gMAtiiifGyw7zj8i7FN1PfpPjucFGtZg CA1lCRgAHYo766uQ0mV0iaP5l4k2JuL7uaQF4DhG88oUB0jsOTiNUe45KPn/WeV/mp5xcW 2Wj74lJO1uAMK/1hcdw6stC+FgTFqwI2i9kzTd+FtnLqZ1vd6aTy8Y6pKTE2CZX4DCAtd8 zTiPqDaAa7AQfweHPFdkFyMEWwFZcXMDFe4IV+qvOssPV9a0TraLPIajnhVptgqQhDKyl+ OTGE2j8s413MmOvIzgLY6bkRtFHqRsHHrx2kqvZSFjnSwBFf0209WFc1lYduuQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1611768553; 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=gV4s82FEuVJugdNoRBb0xE+COjn/uKSW2UKMDbD6jHQ=; b=NaDYvA+wOnqKU2brmmYmjgXx9Os1WNewhM31jbnuz8NnIT52LlmN3YFszE6p1b0tADmnBN v0WyuLWIENFZMKAg== To: linux-omap@vger.kernel.org Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, Thomas Gleixner , "Ahmed S. Darwish" , Sebastian Andrzej Siewior Subject: [PATCH 2/2] video: omapfb: Remove WARN_ON(in_interrupt()). Date: Wed, 27 Jan 2021 18:29:02 +0100 Message-Id: <20210127172902.145335-3-bigeasy@linutronix.de> In-Reply-To: <20210127172902.145335-1-bigeasy@linutronix.de> References: <20210127172902.145335-1-bigeasy@linutronix.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org From: "Ahmed S. Darwish" dsi_sync_vc() uses in_interrupt() to create a warning if the function is used in non-preemptible context. 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 wait_for_completion() function (used in dsi_sync_vc_vp() and dsi_sync_vc_l4() has already a check if it is invoked from proper context. Remove WARN_ON(in_interrupt()) from the driver. Signed-off-by: Ahmed S. Darwish Signed-off-by: Sebastian Andrzej Siewior --- drivers/video/fbdev/omap2/omapfb/dss/dsi.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/video/fbdev/omap2/omapfb/dss/dsi.c b/drivers/video/fbdev/omap2/omapfb/dss/dsi.c index dc34bb04b865c..df90091de75f8 100644 --- a/drivers/video/fbdev/omap2/omapfb/dss/dsi.c +++ b/drivers/video/fbdev/omap2/omapfb/dss/dsi.c @@ -2373,8 +2373,6 @@ static int dsi_sync_vc(struct platform_device *dsidev, int channel) WARN_ON_ONCE(!dsi_bus_is_locked(dsidev)); - WARN_ON(in_interrupt()); - if (!dsi_vc_is_enabled(dsidev, channel)) return 0;