Return-path: Received: from mx1.redhat.com ([209.132.183.28]:42004 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752249AbcKNIoZ (ORCPT ); Mon, 14 Nov 2016 03:44:25 -0500 Date: Mon, 14 Nov 2016 09:42:38 +0100 From: Stanislaw Gruszka To: Mathias Kresin Cc: linux-wireless@vger.kernel.org, Helmut Schaa Subject: Re: [PATCH 04/10] rt2800: do not overwrite WPDMA_GLO_CFG_WP_DMA_BURST_SIZE Message-ID: <20161114084238.GA12372@redhat.com> (sfid-20161114_094429_231059_FB7C3EAB) References: <1478095865-8651-1-git-send-email-sgruszka@redhat.com> <1478095865-8651-5-git-send-email-sgruszka@redhat.com> <48e4790b-7cb3-170e-eda1-11bce9934141@kresin.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <48e4790b-7cb3-170e-eda1-11bce9934141@kresin.me> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Sat, Nov 05, 2016 at 01:55:14PM +0100, Mathias Kresin wrote: > 02.11.2016 15:10, Stanislaw Gruszka: > >We already initlized WPDMA_GLO_CFG_WP_DMA_BURST_SIZE to 3 on > >rt2800_init_registers(). > > > >Signed-off-by: Stanislaw Gruszka > >--- > > drivers/net/wireless/ralink/rt2x00/rt2800lib.c | 1 - > > 1 files changed, 0 insertions(+), 1 deletions(-) > > > >diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c > >index feceb13..9ecdc4c 100644 > >--- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c > >+++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c > >@@ -6756,7 +6756,6 @@ int rt2800_enable_radio(struct rt2x00_dev *rt2x00dev) > > rt2800_register_read(rt2x00dev, WPDMA_GLO_CFG, ®); > > rt2x00_set_field32(®, WPDMA_GLO_CFG_ENABLE_TX_DMA, 1); > > rt2x00_set_field32(®, WPDMA_GLO_CFG_ENABLE_RX_DMA, 1); > >- rt2x00_set_field32(®, WPDMA_GLO_CFG_WP_DMA_BURST_SIZE, 2); > > More a notice than a potential issue since I don't have much > knowledge about the driver/chip internals. > > But WPDMA_GLO_CFG_WP_DMA_BURST_SIZE in rt2800_init_registers() is > set conditionally for rt2x00_is_usb(rt2x00dev), where this one is > set unconditionally. Not sure if this change has side effects. Default HW setting of WP_DMA_BURTS_SIZE is 2, hence patch does not change behaviour on PCI devices. However I looked at RT3290 and RT5592 PCI vendor drivers and there this value is initialized to 3. So I think we can remove is_usb condition in rt2800_init_registers(). Stanislaw