From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH 1/6] sky2: status polling loop (post merge) Date: Thu, 11 Oct 2007 18:29:21 -0700 Message-ID: <20071011182921.1b20505c@freepuppy.rosehill> References: <20071012011951.575936605@linux-foundation.org> <20071012012124.965282742@linux-foundation.org> <20071011.182358.21595252.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from smtp2.linux-foundation.org ([207.189.120.14]:59847 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753533AbXJLB30 (ORCPT ); Thu, 11 Oct 2007 21:29:26 -0400 In-Reply-To: <20071011.182358.21595252.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Handle the corner case where budget is exhausted correctly. And save unnecessary read of index register. Signed-off-by: Stephen Hemminger --- a/drivers/net/sky2.c 2007-10-11 18:26:56.000000000 -0700 +++ b/drivers/net/sky2.c 2007-10-11 18:27:12.000000000 -0700 @@ -2245,15 +2245,13 @@ static inline void sky2_tx_done(struct n } /* Process status response ring */ -static int sky2_status_intr(struct sky2_hw *hw, int to_do) +static int sky2_status_intr(struct sky2_hw *hw, int to_do, u16 idx) { int work_done = 0; unsigned rx[2] = { 0, 0 }; - u16 hwidx = sky2_read16(hw, STAT_PUT_IDX); rmb(); - - while (hw->st_idx != hwidx) { + do { struct sky2_port *sky2; struct sky2_status_le *le = hw->st_le + hw->st_idx; unsigned port = le->css & CSS_LINK_BIT; @@ -2364,7 +2362,7 @@ static int sky2_status_intr(struct sky2_ printk(KERN_WARNING PFX "unknown status opcode 0x%x\n", le->opcode); } - } + } while (hw->st_idx != idx); /* Fully processed status ring so clear irq */ sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ); @@ -2607,6 +2605,7 @@ static int sky2_poll(struct napi_struct struct sky2_hw *hw = container_of(napi, struct sky2_hw, napi); u32 status = sky2_read32(hw, B0_Y2_SP_EISR); int work_done = 0; + u16 idx; if (unlikely(status & Y2_IS_ERROR)) sky2_err_intr(hw, status); @@ -2617,29 +2616,23 @@ static int sky2_poll(struct napi_struct if (status & Y2_IS_IRQ_PHY2) sky2_phy_intr(hw, 1); - for(;;) { - work_done += sky2_status_intr(hw, work_limit); + while ((idx = sky2_read16(hw, STAT_PUT_IDX)) != hw->st_idx) { + work_done += sky2_status_intr(hw, work_limit - work_done, idx); if (work_done >= work_limit) - break; - - /* More work? */ - if (hw->st_idx != sky2_read16(hw, STAT_PUT_IDX)) - continue; - - /* Bug/Errata workaround? - * Need to kick the TX irq moderation timer. - */ - if (sky2_read8(hw, STAT_TX_TIMER_CTRL) == TIM_START) { - sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP); - sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START); - } - - napi_complete(napi); - sky2_read32(hw, B0_Y2_SP_LISR); - break; + goto done; + } + /* Bug/Errata workaround? + * Need to kick the TX irq moderation timer. + */ + if (sky2_read8(hw, STAT_TX_TIMER_CTRL) == TIM_START) { + sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP); + sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START); } + napi_complete(napi); + sky2_read32(hw, B0_Y2_SP_LISR); +done: return work_done; }