On 2020-04-30 08:12, Jeffrey Hugo wrote:
On 4/29/2020 2:52 PM, Bhaumik Bhatt wrote:
While writing any sequence or session identifiers, it is possible that
the host could write a zero value, whereas only non-zero values are
supported writes to those registers. Ensure that host does not write a
non-zero value for those cases.
Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
---
drivers/bus/mhi/core/boot.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
index 0bc9c50..c9971d4 100644
--- a/drivers/bus/mhi/core/boot.c
+++ b/drivers/bus/mhi/core/boot.c
@@ -199,6 +199,9 @@ static int mhi_fw_load_amss(struct mhi_controller
*mhi_cntrl,
mhi_write_reg(mhi_cntrl, base, BHIE_TXVECSIZE_OFFS, mhi_buf->len);
sequence_id = prandom_u32() & BHIE_TXVECSTATUS_SEQNUM_BMSK;
+ if (unlikely(!sequence_id))
+ sequence_id = 1;
Seems like you could use prandom_u32_max(), and add 1 to the result to
eliminate the conditional. What do you think?
Agreed. Done using an internal macro in those places.
+
mhi_write_reg_field(mhi_cntrl, base, BHIE_TXVECDB_OFFS,
BHIE_TXVECDB_SEQNUM_BMSK, BHIE_TXVECDB_SEQNUM_SHFT,
sequence_id);
@@ -254,6 +257,9 @@ static int mhi_fw_load_sbl(struct mhi_controller
*mhi_cntrl,
lower_32_bits(dma_addr));
mhi_write_reg(mhi_cntrl, base, BHI_IMGSIZE, size);
session_id = prandom_u32() & BHI_TXDB_SEQNUM_BMSK;
+ if (unlikely(!session_id))
+ session_id = 1;
+
mhi_write_reg(mhi_cntrl, base, BHI_IMGTXDB, session_id);
read_unlock_bh(pm_lock);
