From f4652752a428f65936a7da5884095ef43a3cac18 Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Tue, 3 Dec 2019 20:30:51 +0100 Subject: scsi: vmw_pvscsi: Fix swiotlb operation With swiotlb, the first byte of the sense buffer may in some cases be uninitialized since we use DMA_FROM_DEVICE, and the device incorrectly doesn't clear it. In those cases, clear it after DMA unmapping. Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Link: https://lore.kernel.org/r/20191203193052.7583-1-thomas_os@shipmail.org Suggested-by: Vishal Bhakta Acked-by: Jim Gill Signed-off-by: Thomas Hellstrom Signed-off-by: Martin K. Petersen --- drivers/scsi/vmw_pvscsi.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'drivers/scsi') diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c index 70008816c91f..8a09d184a320 100644 --- a/drivers/scsi/vmw_pvscsi.c +++ b/drivers/scsi/vmw_pvscsi.c @@ -402,6 +402,17 @@ static int pvscsi_map_buffers(struct pvscsi_adapter *adapter, return 0; } +/* + * The device incorrectly doesn't clear the first byte of the sense + * buffer in some cases. We have to do it ourselves. + * Otherwise we run into trouble when SWIOTLB is forced. + */ +static void pvscsi_patch_sense(struct scsi_cmnd *cmd) +{ + if (cmd->sense_buffer) + cmd->sense_buffer[0] = 0; +} + static void pvscsi_unmap_buffers(const struct pvscsi_adapter *adapter, struct pvscsi_ctx *ctx) { @@ -544,6 +555,8 @@ static void pvscsi_complete_request(struct pvscsi_adapter *adapter, cmd = ctx->cmd; abort_cmp = ctx->abort_cmp; pvscsi_unmap_buffers(adapter, ctx); + if (sdstat != SAM_STAT_CHECK_CONDITION) + pvscsi_patch_sense(cmd); pvscsi_release_context(adapter, ctx); if (abort_cmp) { /* @@ -873,6 +886,7 @@ static void pvscsi_reset_all(struct pvscsi_adapter *adapter) scmd_printk(KERN_ERR, cmd, "Forced reset on cmd %p\n", cmd); pvscsi_unmap_buffers(adapter, ctx); + pvscsi_patch_sense(cmd); pvscsi_release_context(adapter, ctx); cmd->result = (DID_RESET << 16); cmd->scsi_done(cmd); -- cgit