[incubator-nuttx] branch master updated: risc-v/mpfs: usb: fix illegal reads

[xiaoxiang]

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xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 14447600ac risc-v/mpfs: usb: fix illegal reads
14447600ac is described below

commit 14447600aceba792e19120c29d1841325f1d1aa8
Author: Eero Nurkkala <eero.nurkk...@offcode.fi>
AuthorDate: Tue Jul 12 09:27:07 2022 +0300

    risc-v/mpfs: usb: fix illegal reads
    
    With faster data transfer rates, it was seen that the read
    requests occasionally were issued while the USB RX operation
    was actually in progress.  This patch makes sure the system
    doesn't accidentally read the RX fifo while it's being filled
    up, but rather, checks for the RXCSRL_REG_EPN_RX_PKT_RDY_MASK
    flag.  This flag indicates the packet is ready to be read.
    
    Signed-off-by: Eero Nurkkala <eero.nurkk...@offcode.fi>
---
 arch/risc-v/src/mpfs/mpfs_usb.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/risc-v/src/mpfs/mpfs_usb.c b/arch/risc-v/src/mpfs/mpfs_usb.c
index 0c4456673d..6590838ab3 100755
--- a/arch/risc-v/src/mpfs/mpfs_usb.c
+++ b/arch/risc-v/src/mpfs/mpfs_usb.c
@@ -1005,6 +1005,7 @@ static int mpfs_req_read(struct mpfs_usbdev_s *priv,
                          struct mpfs_ep_s *privep, uint16_t recvsize)
 {
   struct mpfs_req_s *privreq;
+  uint16_t reg;
   int epno;
 
   DEBUGASSERT(priv && privep);
@@ -1013,6 +1014,8 @@ static int mpfs_req_read(struct mpfs_usbdev_s *priv,
 
   epno = USB_EPNO(privep->ep.eplog);
 
+  reg = getreg16(MPFS_USB_ENDPOINT(epno) + MPFS_USB_ENDPOINT_RX_CSR_OFFSET);
+
   uint16_t count = getreg16(MPFS_USB_ENDPOINT(epno) +
                             MPFS_USB_ENDPOINT_RX_COUNT_OFFSET);
 
@@ -1026,11 +1029,9 @@ static int mpfs_req_read(struct mpfs_usbdev_s *priv,
       if (privreq == NULL)
         {
           /* When no read requests are pending no EP descriptors are set to
-           * ready. This is fatal at the moment!
+           * ready.
            */
 
-          usbtrace(TRACE_DEVERROR(MPFS_TRACEERR_EPOUTQEMPTY), epno);
-
           privep->epstate = USB_EPSTATE_RXSTOPPED;
           return OK;
         }
@@ -1060,7 +1061,8 @@ static int mpfs_req_read(struct mpfs_usbdev_s *priv,
           privreq = NULL;
         }
 
-      if ((privreq->inflight) && (count != 0))
+      if ((privreq->inflight > 0) && (count != 0) &&
+          (reg & RXCSRL_REG_EPN_RX_PKT_RDY_MASK) != 0)
         {
           /* Update the total number of bytes transferred */