Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754585AbbGTCNO (ORCPT ); Sun, 19 Jul 2015 22:13:14 -0400 Received: from p3plsmtps2ded04.prod.phx3.secureserver.net ([208.109.80.198]:58713 "EHLO p3plsmtps2ded04.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754297AbbGTCNM (ORCPT ); Sun, 19 Jul 2015 22:13:12 -0400 x-originating-ip: 72.167.245.219 From: "K. Y. Srinivasan" To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, vkuznets@redhat.com, jasowang@redhat.com Cc: Christopher Oo , "K. Y. Srinivasan" Subject: [PATCH 3/5] Drivers: hv_vmbus: Fix signal to host condition Date: Sun, 19 Jul 2015 20:37:25 -0700 Message-Id: <1437363447-3554-3-git-send-email-kys@microsoft.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1437363447-3554-1-git-send-email-kys@microsoft.com> References: <1437363419-3511-1-git-send-email-kys@microsoft.com> <1437363447-3554-1-git-send-email-kys@microsoft.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2750 Lines: 77 From: Christopher Oo Fixes a bug where previously hv_ringbuffer_read would pass in the old number of bytes available to read instead of the expected old read index when calculating when to signal to the host that the ringbuffer is empty. Since the previous write size is already saved, also changes the hv_need_to_signal_on_read to use the previously read value rather than recalculating it. Signed-off-by: Christopher Oo Signed-off-by: K. Y. Srinivasan --- drivers/hv/ring_buffer.c | 14 +++----------- 1 files changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 6361d12..70a1a9a 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -103,10 +103,9 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi) * there is room for the producer to send the pending packet. */ -static bool hv_need_to_signal_on_read(u32 old_rd, - struct hv_ring_buffer_info *rbi) +static bool hv_need_to_signal_on_read(u32 prev_write_sz, + struct hv_ring_buffer_info *rbi) { - u32 prev_write_sz; u32 cur_write_sz; u32 r_size; u32 write_loc = rbi->ring_buffer->write_index; @@ -123,10 +122,6 @@ static bool hv_need_to_signal_on_read(u32 old_rd, cur_write_sz = write_loc >= read_loc ? r_size - (write_loc - read_loc) : read_loc - write_loc; - prev_write_sz = write_loc >= old_rd ? r_size - (write_loc - old_rd) : - old_rd - write_loc; - - if ((prev_write_sz < pending_sz) && (cur_write_sz >= pending_sz)) return true; @@ -517,7 +512,6 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, u32 next_read_location = 0; u64 prev_indices = 0; unsigned long flags; - u32 old_read; if (buflen <= 0) return -EINVAL; @@ -528,8 +522,6 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, &bytes_avail_toread, &bytes_avail_towrite); - old_read = bytes_avail_toread; - /* Make sure there is something to read */ if (bytes_avail_toread < buflen) { spin_unlock_irqrestore(&inring_info->ring_lock, flags); @@ -560,7 +552,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, spin_unlock_irqrestore(&inring_info->ring_lock, flags); - *signal = hv_need_to_signal_on_read(old_read, inring_info); + *signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info); return 0; } -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/