Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754403AbYA3Byo (ORCPT ); Tue, 29 Jan 2008 20:54:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752414AbYA3Byd (ORCPT ); Tue, 29 Jan 2008 20:54:33 -0500 Received: from idcmail-mo1so.shaw.ca ([24.71.223.10]:8490 "EHLO pd2mo3so.prod.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750815AbYA3Byc (ORCPT ); Tue, 29 Jan 2008 20:54:32 -0500 Date: Tue, 29 Jan 2008 19:53:19 -0600 From: Robert Hancock Subject: [PATCH] sata_nv: fix for completion handling To: linux-kernel , ide , Jeff Garzik , Tejun Heo , Kuan Luo , Allen Martin Message-id: <479FD88F.8090605@shaw.ca> MIME-version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: 7bit User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2715 Lines: 66 This patch is based on an original patch from Kuan Luo of NVIDIA, posted under subject "fixed a bug of adma in rhel4u5 with HDS7250SASUN500G". His description follows. I've reworked it a bit to avoid some unnecessary repeated checks but it should be functionally identical. "The patch is to solve the error message "ata1: CPB flags CMD err, flags=0x11" when testing HDS7250SASUN500G in rhel4u5. I tested this hd in 2.6.24-rc7 which needed to remove the mask in blacklist to run the ncq and the same error also showed up. I traced the bug and found that the interrupt finished a command (for example, tag=0) when the driver got that adma status is NV_ADMA_STAT_DONE and cpb->resp_flags is NV_CPB_RESP_DONE. However, For this hd, the drive maybe didn't clear bit 0 at this moment. It meaned the hardware had not completely finished the command. If at the same time the driver freed the command(tag 0) and sended another command (tag 0), the error happened. The notifier register is 32-bit register containing notifier value. Value is bit vector containing one bit per tag number (0-31) in corresponding bit positions (bit 0 is for tag 0, etc). When bit is set then ADMA indicates that command with corresponding tag number completed execution. So i added the check notifier code. Sometimes i saw that the notifier reg set some bits , but the adma status set NV_ADMA_STAT_CMD_COMPLETE ,not NV_ADMA_STAT_DONE. So i added the NV_ADMA_STAT_CMD_COMPLETE check code." Signed-off-by: Robert Hancock --- linux-2.6.24-rc7-git3/drivers/ata/sata_nv.c 2008-01-11 17:32:40.000000000 -0600 +++ linux-2.6.24-rc7-git3edit/drivers/ata/sata_nv.c 2008-01-11 17:43:40.000000000 -0600 @@ -1011,14 +1011,20 @@ } if (status & (NV_ADMA_STAT_DONE | - NV_ADMA_STAT_CPBERR)) { - u32 check_commands; + NV_ADMA_STAT_CPBERR | + NV_ADMA_STAT_CMD_COMPLETE)) { + u32 check_commands = notifier_clears[i]; int pos, error = 0; - if (ata_tag_valid(ap->link.active_tag)) - check_commands = 1 << ap->link.active_tag; - else - check_commands = ap->link.sactive; + if (status & NV_ADMA_STAT_CPBERR) { + /* Check all active commands */ + if (ata_tag_valid(ap->link.active_tag)) + check_commands = 1 << + ap->link.active_tag; + else + check_commands = ap-> + link.sactive; + } /** Check CPBs for completed commands */ while ((pos = ffs(check_commands)) && !error) { -- 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/