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 AA31E1BBFEE; Sun, 24 Mar 2024 22:45:13 +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=1711320313; cv=none; b=pxhuQRLrbn+J1LRI7pbBZMJapH8TPWQ3aCMjnHZuP2FEa1+NfwFV7vDevNigenAEXrZkA2uG0nxEwgX2GkAZLAuv67/paLgZHpG41WFvXNlHdtIvn96cja6p6aIHt/Gg4oKuOJ79W42iD+UrwkZQpWz8YQ5jrYksSm42zEgCurA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711320313; c=relaxed/simple; bh=b7pmiGPTXivY91/8QGsotvLKGxTURsI1N8VH15JtETc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZrbtJqKzFEV6wBq4ymX9BbORLSZ7ruJs5YUdxTlL9Lzr54NCgDC2xVaR66TlgC/o+JhSbf5pkzVE6bRrEael3xSEPjWZNL4Yg7qP0l/bFRskJWz0kWfnP2MAUce/NG1zILcQlQ/5rDgHMMAFLC0iwafHKWn4Qe/pp/py3GaV7xw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UbwxvfRk; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UbwxvfRk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CE81C433F1; Sun, 24 Mar 2024 22:45:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711320313; bh=b7pmiGPTXivY91/8QGsotvLKGxTURsI1N8VH15JtETc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UbwxvfRkVGJeYkgPW7OVJaU9/LyAKEKmtQkH1x9JrFsmDvbKTsqCEn2jJ+ULcWFOz sl0KbaoD0Pkks3kVoFx09n4i/GBnaFsf5+7w9dzX3EEnk9RW7GQ5CGVdeQEeawOXsL MJAN6HBOYEcBgRboZ7UFtQV/Z31XUO1gNUCiHzGEmn+POiuu8o3neRIPfNxdLU6/pf pPInypKYuXqp3FKPMqRcSrd1bJJRFArWlU2II8Bg8L8J6m+ZF9D767K2M6u8gzOWL1 GA6+vqztwP/XdBF0sZYU0TQEvnR++Xfsmle7coNnh9bQ2+Z/V7MZEvlm4LJJ3Gex9N /AJ9ZNDJ1mMxw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mathias Nyman , Wesley Cheng , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 6.8 621/715] xhci: update event ring dequeue pointer position to controller correctly Date: Sun, 24 Mar 2024 18:33:20 -0400 Message-ID: <20240324223455.1342824-622-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324223455.1342824-1-sashal@kernel.org> References: <20240324223455.1342824-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Mathias Nyman [ Upstream commit e30e9ad9ed66c049f32ab2ffe38f0b576bebdd2c ] The event ring dequeue pointer field (ERDP) in xHC hardware is used to inform controller how far the driver has processed events on the event ring. In the case all events are handled and event ring is empty then the address of the TRB after the last processed one should be written. This TRB is both the enqueue and dequeue pointer. But in case we are writing the ERDP in the middle of processing several events then ERDP field should be written with the "up to and including" address of the last handled event TRB. Currenly each ERDP write by driver is done as if all events are handled and ring is empty. Fix this by adjusting the order when software dequeue "inc_deq()" is called and hardware dequeue "xhci_update_erst_dequeue()" is updated. Details in xhci 1.2 specification section 4.9.4: "System software shall write the Event Ring Dequeue Pointer (ERDP) register to inform the xHC that it has completed the processing of Event TRBs up to and including the Event TRB referenced by the ERDP. The detection of a Cycle bit mismatch in an Event TRB processed by software indicates the location of the xHC Event Ring Enqueue Pointer and that the Event Ring is empty. Software shall write the ERDP with the address of this TRB to indicate that it has processed all Events in the ring" This change depends on fixes made to relocate inc_deq() calls captured in the below commits: commit 3321f84bfae0 ("xhci: simplify event ring dequeue tracking for transfer events") commit d1830364e963 ("xhci: Simplify event ring dequeue pointer update for port change events") Fixes: dc0ffbea5729 ("usb: host: xhci: update event ring dequeue pointer on purpose") Signed-off-by: Mathias Nyman Signed-off-by: Wesley Cheng Link: https://lore.kernel.org/r/20240217001017.29969-6-quic_wcheng@quicinc.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/usb/host/xhci-ring.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 129d2e83034c1..61bd29dd71a2f 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -3022,9 +3022,6 @@ static int xhci_handle_event(struct xhci_hcd *xhci, struct xhci_interrupter *ir) return 0; } - /* Update SW event ring dequeue pointer */ - inc_deq(xhci, ir->event_ring); - /* Are there more items on the event ring? Caller will call us again to * check. */ @@ -3147,15 +3144,21 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd) * that clears the EHB. */ while (xhci_handle_event(xhci, ir) > 0) { - if (event_loop++ < TRBS_PER_SEGMENT / 2) - continue; - xhci_update_erst_dequeue(xhci, ir, false); + /* + * If half a segment of events have been handled in one go then + * update ERDP, and force isoc trbs to interrupt more often + */ + if (event_loop++ > TRBS_PER_SEGMENT / 2) { + xhci_update_erst_dequeue(xhci, ir, false); + + if (ir->isoc_bei_interval > AVOID_BEI_INTERVAL_MIN) + ir->isoc_bei_interval = ir->isoc_bei_interval / 2; - /* ring is half-full, force isoc trbs to interrupt more often */ - if (ir->isoc_bei_interval > AVOID_BEI_INTERVAL_MIN) - ir->isoc_bei_interval = ir->isoc_bei_interval / 2; + event_loop = 0; + } - event_loop = 0; + /* Update SW event ring dequeue pointer */ + inc_deq(xhci, ir->event_ring); } xhci_update_erst_dequeue(xhci, ir, true); -- 2.43.0