From mboxrd@z Thu Jan 1 00:00:00 1970 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 5B8091FC7; Wed, 25 Feb 2026 01:44:57 +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=1771983897; cv=none; b=VjVw33jdfpd7dKvHQ0q/oR6oE9QA5vku9VHrRXNkVd+LY1hrPN3W3scZnRcltih8RS7yJcc1mFhWJV7P9XY8gOmxRtk6JrQFWIx+NudqyKAGk9T9Z2cDVw+uOptOLCWS25Fl3tOxAvAqXhu4HR6vYf0UciknuLfmUQUPhLUQG5k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983897; c=relaxed/simple; bh=pW+rBh22cxtrNjhT+jOpJvLMKmXRniaRs8UcTzTUXSE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m/KfTGNTZb1Nt3zxisIqJlRIYjCaUVsQ05na7HWUsqZsvhj9anN+euClUsuUyi3+YEEbdajKTWsJWpWZE+smoEkJ4bUyBOCZ7LP0Q/jZ9X5sGAW38BBAUvWqV8wk+TmAEONXnY6oDa+1GYVkMLgnOuFtOYSPYhkxM8QexnNs0yY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MgiMGTwA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="MgiMGTwA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBE98C116D0; Wed, 25 Feb 2026 01:44:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771983897; bh=pW+rBh22cxtrNjhT+jOpJvLMKmXRniaRs8UcTzTUXSE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MgiMGTwA6VWJwoKJHgHsZ7vOos6n3THsYp8Fnvd3X2om+Rblxa2xonHGT/11TmCE/ /YFvLMqq7oof8yWtg/FVSkJ3sGe3WZuixiuDmK1tRB1i4Pl8pua+JUAPRx6X0i/j7S rwTSIRdEzomKVbF6brpT6qodQpadZzSOAkvYMrkI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Steven Price , Boris Brezillon , Sasha Levin Subject: [PATCH 6.18 168/641] drm/panthor: Recover from panthor_gpu_flush_caches() failures Date: Tue, 24 Feb 2026 17:18:14 -0800 Message-ID: <20260225012353.124588214@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012348.915798704@linuxfoundation.org> References: <20260225012348.915798704@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Boris Brezillon [ Upstream commit 3c0a60195b37af83bbbaf223cd3a78945bace49e ] We have seen a few cases where the whole memory subsystem is blocked and flush operations never complete. When that happens, we want to: - schedule a reset, so we can recover from this situation - in the reset path, we need to reset the pending_reqs so we can send new commands after the reset - if more panthor_gpu_flush_caches() operations are queued after the timeout, we skip them and return -EIO directly to avoid needless waits (the memory block won't miraculously work again) Note that we drop the WARN_ON()s because these hangs can be triggered with buggy GPU jobs created by the UMD, and there's no way we can prevent it. We do keep the error messages though. v2: - New patch v3: - Collect R-b - Explicitly mention the fact we dropped the WARN_ON()s in the commit message v4: - No changes Fixes: 5cd894e258c4 ("drm/panthor: Add the GPU logical block") Reviewed-by: Steven Price Link: https://patch.msgid.link/20251128084841.3804658-4-boris.brezillon@collabora.com Signed-off-by: Boris Brezillon Signed-off-by: Sasha Levin --- drivers/gpu/drm/panthor/panthor_gpu.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c index db69449a5be09..b92c9e738dbfa 100644 --- a/drivers/gpu/drm/panthor/panthor_gpu.c +++ b/drivers/gpu/drm/panthor/panthor_gpu.c @@ -259,38 +259,42 @@ int panthor_gpu_l2_power_on(struct panthor_device *ptdev) int panthor_gpu_flush_caches(struct panthor_device *ptdev, u32 l2, u32 lsc, u32 other) { - bool timedout = false; unsigned long flags; + int ret = 0; /* Serialize cache flush operations. */ guard(mutex)(&ptdev->gpu->cache_flush_lock); spin_lock_irqsave(&ptdev->gpu->reqs_lock, flags); - if (!drm_WARN_ON(&ptdev->base, - ptdev->gpu->pending_reqs & GPU_IRQ_CLEAN_CACHES_COMPLETED)) { + if (!(ptdev->gpu->pending_reqs & GPU_IRQ_CLEAN_CACHES_COMPLETED)) { ptdev->gpu->pending_reqs |= GPU_IRQ_CLEAN_CACHES_COMPLETED; gpu_write(ptdev, GPU_CMD, GPU_FLUSH_CACHES(l2, lsc, other)); + } else { + ret = -EIO; } spin_unlock_irqrestore(&ptdev->gpu->reqs_lock, flags); + if (ret) + return ret; + if (!wait_event_timeout(ptdev->gpu->reqs_acked, !(ptdev->gpu->pending_reqs & GPU_IRQ_CLEAN_CACHES_COMPLETED), msecs_to_jiffies(100))) { spin_lock_irqsave(&ptdev->gpu->reqs_lock, flags); if ((ptdev->gpu->pending_reqs & GPU_IRQ_CLEAN_CACHES_COMPLETED) != 0 && !(gpu_read(ptdev, GPU_INT_RAWSTAT) & GPU_IRQ_CLEAN_CACHES_COMPLETED)) - timedout = true; + ret = -ETIMEDOUT; else ptdev->gpu->pending_reqs &= ~GPU_IRQ_CLEAN_CACHES_COMPLETED; spin_unlock_irqrestore(&ptdev->gpu->reqs_lock, flags); } - if (timedout) { + if (ret) { + panthor_device_schedule_reset(ptdev); drm_err(&ptdev->base, "Flush caches timeout"); - return -ETIMEDOUT; } - return 0; + return ret; } /** @@ -330,6 +334,7 @@ int panthor_gpu_soft_reset(struct panthor_device *ptdev) return -ETIMEDOUT; } + ptdev->gpu->pending_reqs = 0; return 0; } -- 2.51.0