From nobody Fri Dec 19 19:09:37 2025 Received: from mail-lf1-f44.google.com (mail-lf1-f44.google.com [209.85.167.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AEB97170A1C for ; Mon, 12 Aug 2024 10:32:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.44 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723458770; cv=none; b=cmPVqyoxE6SFEviWllNnRLm9E+/Eb/YwzCsPyZ7N+b+A8eMI08f8sUJpg3BEK6IJr3Zz/a+qZOUjqbWgbweLQ1fKP0D9YR4cZPUQjubcpGvbVxNMhdlksFubXO5DwGnDJ8WSIykljszS/NvIue1vCd/UPB1nUHk3SSENxPiGacQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723458770; c=relaxed/simple; bh=rSCBaIXJPRajVS8xJXyFx6JrCeK2HqadPitU/xd6N7c=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=CeDL3jB2nompQ9bkKsTuEF3Kq/6vrmJCpDAWpOuwRC1Yzng7dY1IYnrfpws1sQTHFZjdvQxYi1pDJGtzZ+kuObSeOCobRJqRq8GvxBsf1FqjTOt4IsbVd1X5FstT+8mJkrW0iZ8C3nkZgXYu4ehllRxmR1HrNvbHYyy3xlrqXPw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=YFneBiXq; arc=none smtp.client-ip=209.85.167.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="YFneBiXq" Received: by mail-lf1-f44.google.com with SMTP id 2adb3069b0e04-52efa16aad9so5351870e87.0 for ; Mon, 12 Aug 2024 03:32:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1723458767; x=1724063567; darn=vger.kernel.org; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=i1IfJ9u3yUX0iZ4jMFGItrUi/pvd+46Zvfr+ViX5sCk=; b=YFneBiXqyMRD4q8pRqG5qxENFcul71xLC1DuNdGfKSUE9TsZkOrRUhuP4jHuD2x3Y6 x0NRGs97rn9D5TrV7p29oUoMHFyGShc1H+y32pIiJwbqxzkRIgTUEjmjPpXPylKAl2/F A0zyV8p3ywc/ZPGB3geyFi+V4N4j94L8znNc5tZxfzH3bkO/Hp4c4ytCyu0Y2WtBhL8j V1AwEIp5h4kRGb2h8dwbktmEKwYTKQ4oUVKqXD1d7wiB7aRNUxZg4YyUB+baG2ZWplfc bj6cBbu5nBF3R+d4KPchJAtQ5jMb300PGLB8QeVbZ731DL4xt8hgdVo2PSAGkyQISpBZ FfXw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723458767; x=1724063567; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=i1IfJ9u3yUX0iZ4jMFGItrUi/pvd+46Zvfr+ViX5sCk=; b=MzZCcppmaRvh+goz7uTEaIY2WKtIYY4/nzM9thJFfs9leMziDfIJxu9WGTcNEnrFdA 4e8mMtTq2rlrEKnyt+vTMsSI0Lg3oB36S/ySUaH+UcuCzl689M2yt/LeMl2XELpAfKjf 9cYkNOCrKr40FIfFW7wa6YszF3Iyw/XUHmTkmmQwQrGvJe0mASiEVov6x7sLhmHowuqJ 7ezGypHVz3qVIp8/5o1HIyzssTChPGqMxMo2GVzD0/LAc5Y95HFQvZMWE+Uf7agd3Hm+ ITlDM4XGKU+ueSxPv58ju2xI6BZG5c7NYWMSDeBC7hJ8qXFQ9Sep0IJpc1pYlleDXnpD M33Q== X-Forwarded-Encrypted: i=1; AJvYcCVnYclAd2iMmSXp95Rb8iXDhTlUYE5CBC/e9UihWty0ZutbHRuwnfIWbFwrA3jfRLup7u9dPHIID/eC1tH6sBadfRNM59EEYWbYz28l X-Gm-Message-State: AOJu0YycGMaERNCQ70CH7Ava7fEpyncj+agI9bkFBvQEbVlfez2UeLso TR9xCEnidWD8X5NTmSAmLn+1RYJfW+CyiJ2OKYmnOr+auJBihhIt0a1JBb7iKLU= X-Google-Smtp-Source: AGHT+IHzgJxlWNmlpbcyADFmPoi5Gdg+YYXbOVyXdQhr3/VvVj6WyK6nEwaJnWhwJoNlT7DEw3b1qw== X-Received: by 2002:a05:6512:ea5:b0:530:da95:b54c with SMTP id 2adb3069b0e04-530ee985dfdmr5817998e87.23.1723458766440; Mon, 12 Aug 2024 03:32:46 -0700 (PDT) Received: from localhost ([196.207.164.177]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5bd1a602da2sm2158926a12.93.2024.08.12.03.32.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Aug 2024 03:32:46 -0700 (PDT) Date: Mon, 12 Aug 2024 11:29:38 +0300 From: Dan Carpenter To: Thomas Zimmermann Cc: Dave Airlie , Jocelyn Falempe , Maarten Lankhorst , Maxime Ripard , David Airlie , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH v3] drm/ast: astdp: fix loop timeout check Message-ID: <1ba8da25-2d09-4924-a4ff-c0714bfbb192@stanley.mountain> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline X-Mailer: git-send-email haha only kidding Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This code has an issue because it loops until "i" is set to UINT_MAX but the test for failure assumes that "i" is set to zero. The result is that it will only print an error message if we succeed on the very last try. Reformat the loop to count forwards instead of backwards. Fixes: 2281475168d2 ("drm/ast: astdp: Perform link training during atomic_e= nable") Signed-off-by: Dan Carpenter Reviewed-by: Thomas Zimmermann --- v3: V2 had the same bug but just without the always true if (i) statement. Remove the final sleep. v2: In V1, I introduced a bug where it would msleep(100) after failure and that is a pointless thing to do. Also change the loop to a for loo= p. --- drivers/gpu/drm/ast/ast_dp.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/ast/ast_dp.c b/drivers/gpu/drm/ast/ast_dp.c index 5d07678b502c..ca022c287785 100644 --- a/drivers/gpu/drm/ast/ast_dp.c +++ b/drivers/gpu/drm/ast/ast_dp.c @@ -146,18 +146,19 @@ void ast_dp_power_on_off(struct drm_device *dev, bool= on) void ast_dp_link_training(struct ast_device *ast) { struct drm_device *dev =3D &ast->base; - unsigned int i =3D 10; + int i; =20 - while (i--) { - u8 vgacrdc =3D ast_get_index_reg(ast, AST_IO_VGACRI, 0xdc); + for (i =3D 0; i < 10; i++) { + u8 vgacrdc; =20 - if (vgacrdc & AST_IO_VGACRDC_LINK_SUCCESS) - break; if (i) msleep(100); + + vgacrdc =3D ast_get_index_reg(ast, AST_IO_VGACRI, 0xdc); + if (vgacrdc & AST_IO_VGACRDC_LINK_SUCCESS) + return; } - if (!i) - drm_err(dev, "Link training failed\n"); + drm_err(dev, "Link training failed\n"); } =20 void ast_dp_set_on_off(struct drm_device *dev, bool on) --=20 2.43.0