From: Dan Williams Date: Thu, 6 Feb 2014 20:23:15 +0000 (-0800) Subject: [SCSI] isci: fix needless ata reset escalations X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2193b1b16cc7c690f74f917c50004dd00c99088e;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git [SCSI] isci: fix needless ata reset escalations isci is needlessly tying libata's hands by returning SAM_STAT_CHECK_CONDITION to some ata errors. Instead, prefer SAS_PROTO_RESPONSE to let libata (via sas_ata_task_done()) disposition the device-to-host fis. For example isci is triggering an HSM Violation where AHCI is showing a simple media error for the same bus condition: isci: ata7.00: failed command: READ VERIFY SECTOR(S) ata7.00: cmd 40/00:01:00:00:00/00:00:00:00:00/e0 tag 0 res 01/04:00:00:00:00/00:00:00:00:00/e0 Emask 0x3 (HSM violation) ahci: ata6.00: failed command: READ VERIFY SECTOR(S) ata6.00: cmd 40/00:01:00:00:00/00:00:00:00:00/e0 tag 0 res 51/40:01:00:00:00/00:00:00:00:00/e0 Emask 0x9 (media error) Note that the isci response matches this from sas_ata_task_done(): /* We saw a SAS error. Send a vague error. */ [..] dev->sata_dev.fis[3] = 0x04; /* status err */ dev->sata_dev.fis[2] = ATA_ERR; The end effect is that isci is needlessly triggering hard resets when they are not necessary. Reported-by: Xun Ni Tested-by: Nelson Cheng Acked-by: Lukasz Dorau Signed-off-by: Dan Williams Signed-off-by: James Bottomley --- diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c index 99d2930b18c8..56e38096f0c4 100644 --- a/drivers/scsi/isci/request.c +++ b/drivers/scsi/isci/request.c @@ -2723,13 +2723,9 @@ static void isci_process_stp_response(struct sas_task *task, struct dev_to_host_ memcpy(resp->ending_fis, fis, sizeof(*fis)); ts->buf_valid_size = sizeof(*resp); - /* If the device fault bit is set in the status register, then - * set the sense data and return. - */ - if (fis->status & ATA_DF) + /* If an error is flagged let libata decode the fis */ + if (ac_err_mask(fis->status)) ts->stat = SAS_PROTO_RESPONSE; - else if (fis->status & ATA_ERR) - ts->stat = SAM_STAT_CHECK_CONDITION; else ts->stat = SAM_STAT_GOOD;