From patchwork Wed Jan 29 09:51:48 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans Verkuil X-Patchwork-Id: 860736 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2447318FDCE for ; Wed, 29 Jan 2025 09:51:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738144311; cv=none; b=TnDPmq7IyrlZse+4n2t0WFp1GCIufnmntAEWwVw+BxtovDxYaBN0BPiwGvUReWvoMniwJjUd3VumIoN3S5gH1nwJA7nLZKdvbE+LXMNZ99eNWeYf3aRjLIi6PlKLoDRkmwfnGIbiYiZoD1HDhb7bxDQOManr69D0tOfRjeqM3xg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738144311; c=relaxed/simple; bh=STjLT2/gWaqQpvjCmQ57q48jZA4UXIfmHFtZkRx0DuA=; h=Message-ID:Date:MIME-Version:To:Cc:From:Subject:Content-Type; b=XfwPPWD70l7k4Ob4Rtr7Qs6jmXA6r7dkgLHCFMv8CSgCB3yIoJ8hfxtTjh09PaofR0Tx/FuOdOjd5U8xQGx/rVq5AdcylOtwC0MnuVSjOr64fCgHjRvCrzvMtklaVEUmn/3s4JK6PXOb0JWsCwVQT+yBucEr8hB+y7CBDda1q/M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11C4DC4CED3; Wed, 29 Jan 2025 09:51:49 +0000 (UTC) Message-ID: <361bb03d-1691-4e23-84da-0861ead5dbdc@xs4all.nl> Date: Wed, 29 Jan 2025 10:51:48 +0100 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US, nl To: "dri-devel@lists.freedesktop.org" Cc: Linux Media Mailing List , Farblos From: Hans Verkuil Subject: [PATCH] gpu: drm_dp_cec: fix broken CEC adapter properties check Autocrypt: addr=hverkuil@xs4all.nl; keydata= xsFNBFQ84W0BEAC7EF1iL4s3tY8cRTVkJT/297h0Hz0ypA+ByVM4CdU9sN6ua/YoFlr9k0K4 BFUlg7JzJoUuRbKxkYb8mmqOe722j7N3HO8+ofnio5cAP5W0WwDpM0kM84BeHU0aPSTsWiGR yw55SOK2JBSq7hueotWLfJLobMWhQii0Zd83hGT9SIt9uHaHjgwmtTH7MSTIiaY6N14nw2Ud C6Uykc1va0Wqqc2ov5ihgk/2k2SKa02ookQI3e79laOrbZl5BOXNKR9LguuOZdX4XYR3Zi6/ BsJ7pVCK9xkiVf8svlEl94IHb+sa1KrlgGv3fn5xgzDw8Z222TfFceDL/2EzUyTdWc4GaPMC E/c1B4UOle6ZHg02+I8tZicjzj5+yffv1lB5A1btG+AmoZrgf0X2O1B96fqgHx8w9PIpVERN YsmkfxvhfP3MO3oHh8UY1OLKdlKamMneCLk2up1Zlli347KMjHAVjBAiy8qOguKF9k7HOjif JCLYTkggrRiEiE1xg4tblBNj8WGyKH+u/hwwwBqCd/Px2HvhAsJQ7DwuuB3vBAp845BJYUU3 06kRihFqbO0vEt4QmcQDcbWINeZ2zX5TK7QQ91ldHdqJn6MhXulPKcM8tCkdD8YNXXKyKqNl UVqXnarz8m2JCbHgjEkUlAJCNd6m3pfESLZwSWsLYL49R5yxIwARAQABzSFIYW5zIFZlcmt1 aWwgPGh2ZXJrdWlsQHhzNGFsbC5ubD7CwZUEEwEKAD8CGwMGCwkIBwMCBhUIAgkKCwQWAgMB Ah4BAheAFiEEBSzee8IVBTtonxvKvS1hSGYUO0wFAmaU3GkFCRf7lXsACgkQvS1hSGYUO0wZ cw//cLMiaV+p2rCyzdpDjWon2XD6M646THYvqXLb9eVWicFlVG78kNtHrHyEWKPhN3OdWWjn kOzXseVR/nS6vZvqCaT3rwgh3ZMb0GvOQk1/7V8UbcIERy036AjQoZmKo5tEDIv48MSvqxjj H6wbKXbCyvnIwpGICLyb0xAwvvpTaJkwZjvGqeo5EL0Z+cQ8fCelfKNO5CFFP3FNd3dH8wU6 CHRtdZE03iIVEWpgCTjsG2zwsX/CKfPx0EKcrQajW3Tc50Jm0uuRUEKCVphlYORAPtFAF1dj Ly8zpN1bEXH+0FDXe/SHhzbvgS4sL0J4KQCCZ/GcbKh/vsDC1VLsGS5C7fKOhAtOkUPWRjF+ kOEEcTOROMMvSUVokO+gCdb9nA/e3WMgiTwWRumWy5eCEnCpM9+rfI2HzTeACrVgGEDkOTHW eaGHEy8nS9a25ejQzsBhi+T7MW53ZTIjklR7dFl/uuK+EJ6DLbDpVbwyYo2oeiwP+sf8/Rgv WfJv4wzfUo/JABwrsbfWfycVZwFWBzqq+TaKFkMPm017dkLdg4MzxvvTMP7nKfJxU1bQ2OOr xkPk5KDcz+aRYBvTqEXgYZ6OZtnOUFKD+uPlbWf68vuz/1iFbQYnNJkTxwWhiIMN7BULK74d Ek89MU7JlbYNSv0v21lRF+uDo0J6zyoTt0ZxSPzOwU0EVDzhbQEQANzLiI6gHkIhBQKeQaYs p2SSqF9c++9LOy5x6nbQ4s0X3oTKaMGfBZuiKkkU6NnHCSa0Az5ScRWLaRGu1PzjgcVwzl5O sDawR1BtOG/XoPRNB2351PRp++W8TWo2viYYY0uJHKFHML+ku9q0P+NkdTzFGJLP+hn7x0RT DMbhKTHO3H2xJz5TXNE9zTJuIfGAz3ShDpijvzYieY330BzZYfpgvCllDVM5E4XgfF4F/N90 wWKu50fMA01ufwu+99GEwTFVG2az5T9SXd7vfSgRSkzXy7hcnxj4IhOfM6Ts85/BjMeIpeqy TDdsuetBgX9DMMWxMWl7BLeiMzMGrfkJ4tvlof0sVjurXibTibZyfyGR2ricg8iTbHyFaAzX 2uFVoZaPxrp7udDfQ96sfz0hesF9Zi8d7NnNnMYbUmUtaS083L/l2EDKvCIkhSjd48XF+aO8 VhrCfbXWpGRaLcY/gxi2TXRYG9xCa7PINgz9SyO34sL6TeFPSZn4bPQV5O1j85Dj4jBecB1k z2arzwlWWKMZUbR04HTeAuuvYvCKEMnfW3ABzdonh70QdqJbpQGfAF2p4/iCETKWuqefiOYn pR8PqoQA1DYv3t7y9DIN5Jw/8Oj5wOeEybw6vTMB0rrnx+JaXvxeHSlFzHiD6il/ChDDkJ9J /ejCHUQIl40wLSDRABEBAAHCwXwEGAEKACYCGwwWIQQFLN57whUFO2ifG8q9LWFIZhQ7TAUC ZpTcxwUJF/uV2gAKCRC9LWFIZhQ7TMlPD/9ppgrN4Z9gXta9IdS8a+0E7lj/dc0LnF9T6MMq aUC+CFffTiOoNDnfXh8sfsqTjAT50TsVpdlH6YyPlbU5FR8bC8wntrJ6ZRWDdHJiCDLqNA/l GVtIKP1YW8fA01thMcVUyQCdVUqnByMJiJQDzZYrX+E/YKUTh2RL5Ye0foAGE7SGzfZagI0D OZN92w59e1Jg3zBhYXQIjzBbhGIy7usBfvE882GdUbP29bKfTpcOKkJIgO6K+w82D/1d5TON SD146+UySmEnjYxHI8kBYaZJ4ubyYrDGgXT3jIBPq8i9iZP3JSeZ/0F9UIlX4KeMSG8ymgCR SqL1y9pl9R2ewCepCahEkTT7IieGUzJZz7fGUaxrSyexPE1+qNosfrUIu3yhRA6AIjhwPisl aSwDxLI6qWDEQeeWNQaYUSEIFQ5XkZxd/VN8JeMwGIAq17Hlym+JzjBkgkm1LV9LXw9D8MQL e8tSeEXX8BZIen6y/y+U2CedzEsMKGjy5WNmufiPOzB3q2JwFQCw8AoNic7soPN9CVCEgd2r XS+OUZb8VvEDVRSK5Yf79RveqHvmhAdNOVh70f5CvwR/bfX/Ei2Szxz47KhZXpn1lxmcds6b LYjTAZF0anym44vsvOEuQg3rqxj/7Hiz4A3HIkrpTWclV6ru1tuGp/ZJ7aY8bdvztP2KTw== If the hotplug detect of a display is low for longer than one second (configurable through drm_dp_cec_unregister_delay), then the CEC adapter is unregistered since we assume the display was disconnected. If the HPD went low for less than one second, then we check if the properties of the CEC adapter have changed, since that indicates that we actually switch to new hardware and we have to unregister the old CEC device and register a new one. Unfortunately, the test for changed properties was written poorly, and after a new CEC capability was added to the CEC core code the test always returned true (i.e. the properties had changed). As a result the CEC device was unregistered and re-registered for every HPD toggle. If the CEC remote controller integration was also enabled (CONFIG_MEDIA_CEC_RC was set), then the corresponding input device was also unregistered and re-registered. As a result the input device in /sys would keep incrementing its number, e.g.: /sys/devices/pci0000:00/0000:00:08.1/0000:e7:00.0/rc/rc0/input20 Since short HPD toggles are common, the number could over time get into the thousands. While not a serious issue (i.e. nothing crashes), it is not intended to work that way. This patch changes the test so that it only checks for the single CEC capability that can actually change, and it ignores any other capabilities, so this is now safe as well if new caps are added in the future. With the changed test the bit under #ifndef CONFIG_MEDIA_CEC_RC can be dropped as well, so that's a nice cleanup. Signed-off-by: Hans Verkuil Reported-by: Farblos --- Jens (aka Farblos), can you test this patch? --- drivers/gpu/drm/display/drm_dp_cec.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/display/drm_dp_cec.c b/drivers/gpu/drm/display/drm_dp_cec.c index 007ceb281d00..56a4965e518c 100644 --- a/drivers/gpu/drm/display/drm_dp_cec.c +++ b/drivers/gpu/drm/display/drm_dp_cec.c @@ -311,16 +311,6 @@ void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address) if (!aux->transfer) return; -#ifndef CONFIG_MEDIA_CEC_RC - /* - * CEC_CAP_RC is part of CEC_CAP_DEFAULTS, but it is stripped by - * cec_allocate_adapter() if CONFIG_MEDIA_CEC_RC is undefined. - * - * Do this here as well to ensure the tests against cec_caps are - * correct. - */ - cec_caps &= ~CEC_CAP_RC; -#endif cancel_delayed_work_sync(&aux->cec.unregister_work); mutex_lock(&aux->cec.lock); @@ -337,7 +327,9 @@ void drm_dp_cec_attach(struct drm_dp_aux *aux, u16 source_physical_address) num_las = CEC_MAX_LOG_ADDRS; if (aux->cec.adap) { - if (aux->cec.adap->capabilities == cec_caps && + /* Check if the adapter properties have changed */ + if ((aux->cec.adap->capabilities & CEC_CAP_MONITOR_ALL) == + (cec_caps & CEC_CAP_MONITOR_ALL) && aux->cec.adap->available_log_addrs == num_las) { /* Unchanged, so just set the phys addr */ cec_s_phys_addr(aux->cec.adap, source_physical_address, false);