From 193f33d061d2e8b8297a1870f3134491a9251874 Mon Sep 17 00:00:00 2001 From: Avri Altman Date: Thu, 20 May 2021 15:04:35 +0300 Subject: [PATCH] FROMGIT: scsi: ufshpb: Use a correct max multi chunk In HPB2.0, if pre_req_min_tr_len < transfer_len < pre_req_max_tr_len the driver is expected to send a HPB-WRITE-BUFFER companion to HPB-READ. The upper bound should fit into a single byte, regardless of bMAX_ DATA_SIZE_FOR_HPB_SINGLE_CMD which being an attribute (u32) can be significantly larger. To further illustrate the issue let us consider the following scenario: - SCSI_DEFAULT_MAX_SECTORS is 1024 limiting the IO chunks to 512KB - The OEM changes scsi_host_template .max_sectors to be 2048, which allows a 1M requests: transfer_len = 256 - pre_req_max_tr_len = HPB_MULTI_CHUNK_HIGH = 256 - ufshpb_is_supported_chunk returns true (256 <= 256) - WARN_ON_ONCE(transfer_len > HPB_MULTI_CHUNK_HIGH) doesn't warn - ufshpb_set_hpb_read_to_upiu cast transfer_len to u8: transfer_len = 0 - the command is failing with illegal request Link: https://lore.kernel.org/r/20210808090024.21721-3-avri.altman@wdc.com Fixes: 41d8a9333cc9 (scsi: ufs: ufshpb: Add HPB 2.0 support) (cherry picked from commit 07106f86ae13d9197bfd38c2d47743304b14099e git: //git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git for-next) Signed-off-by: Avri Altman Change-Id: I0dc568020a0fe6c4ddf6952f89ad5230770fd7f3 --- drivers/scsi/ufs/ufshpb.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/ufs/ufshpb.h b/drivers/scsi/ufs/ufshpb.h index c74a6c35a446..6df317dfe034 100644 --- a/drivers/scsi/ufs/ufshpb.h +++ b/drivers/scsi/ufs/ufshpb.h @@ -32,7 +32,7 @@ /* hpb support chunk size */ #define HPB_LEGACY_CHUNK_HIGH 1 #define HPB_MULTI_CHUNK_LOW 7 -#define HPB_MULTI_CHUNK_HIGH 256 +#define HPB_MULTI_CHUNK_HIGH 255 /* hpb vender defined opcode */ #define UFSHPB_READ 0xF8