[PATCH] ice: retry reading NVM if admin queue returns EBUSY

[PATCH] ice: retry reading NVM if admin queue returns EBUSY

[Robert Malz]

When the admin queue command to read NVM returns EBUSY, the driver
currently treats it as a fatal error and aborts the entire read
operation. This can cause spurious NVM read failures during periods of
high firmware activity.

Add retry logic to ice_read_flat_nvm() that handles EBUSY responses
from the admin queue. When an EBUSY error is encountered, release the
NVM resource lock, wait for ICE_SQ_SEND_DELAY_TIME_MS, re-acquire it,
and retry the failed read. The retry is attempted up to
ICE_SQ_SEND_MAX_EXECUTE times before giving up.

Code was extracted from OOT ice driver 1.15.4 release. Additional
change was made to reset last_cmd in case of retry to make sure that
all commands are retried properly.

Fixes: e94509906d6b ("ice: create function to read a section of the NVM and Shadow RAM")
Signed-off-by: Robert Malz <robert.malz@canonical.com>
---
 drivers/net/ethernet/intel/ice/ice_nvm.c | 25 +++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_nvm.c b/drivers/net/ethernet/intel/ice/ice_nvm.c
index 7e187a804dfa..cbe21ef9d18e 100644
--- a/drivers/net/ethernet/intel/ice/ice_nvm.c
+++ b/drivers/net/ethernet/intel/ice/ice_nvm.c
@@ -67,6 +67,7 @@ ice_read_flat_nvm(struct ice_hw *hw, u32 offset, u32 *length, u8 *data,
 {
 	u32 inlen = *length;
 	u32 bytes_read = 0;
+	int retry_cnt = 0;
 	bool last_cmd;
 	int status;
 
@@ -96,11 +97,25 @@ ice_read_flat_nvm(struct ice_hw *hw, u32 offset, u32 *length, u8 *data,
 					 offset, read_size,
 					 data + bytes_read, last_cmd,
 					 read_shadow_ram, NULL);
-		if (status)
-			break;
-
-		bytes_read += read_size;
-		offset += read_size;
+		if (status) {
+			if (hw->adminq.sq_last_status != ICE_AQ_RC_EBUSY ||
+			    retry_cnt > ICE_SQ_SEND_MAX_EXECUTE)
+				break;
+			ice_debug(hw, ICE_DBG_NVM,
+				  "NVM read EBUSY error, retry %d\n",
+				  retry_cnt + 1);
+			last_cmd = false;
+			ice_release_nvm(hw);
+			msleep(ICE_SQ_SEND_DELAY_TIME_MS);
+			status = ice_acquire_nvm(hw, ICE_RES_READ);
+			if (status)
+				break;
+			retry_cnt++;
+		} else {
+			bytes_read += read_size;
+			offset += read_size;
+			retry_cnt = 0;
+		}
 	} while (!last_cmd);
 
 	*length = bytes_read;
-- 
2.34.1

Re: [PATCH] ice: retry reading NVM if admin queue returns EBUSY

[kernel test robot]

Hi Robert,

kernel test robot noticed the following build errors:

[auto build test ERROR on tnguy-next-queue/dev-queue]
[also build test ERROR on tnguy-net-queue/dev-queue linus/master v7.1 next-20260616]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Robert-Malz/ice-retry-reading-NVM-if-admin-queue-returns-EBUSY/20260616-185349
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue.git dev-queue
patch link:    https://lore.kernel.org/r/20260616104521.1545053-1-robert.malz%40canonical.com
patch subject: [PATCH] ice: retry reading NVM if admin queue returns EBUSY
config: x86_64-rhel-9.4 (https://download.01.org/0day-ci/archive/20260616/202606162237.EIrFZKip-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260616/202606162237.EIrFZKip-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202606162237.EIrFZKip-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/net/ethernet/intel/ice/ice_nvm.c: In function 'ice_read_flat_nvm':
>> drivers/net/ethernet/intel/ice/ice_nvm.c:101:58: error: 'ICE_AQ_RC_EBUSY' undeclared (first use in this function); did you mean 'LIBIE_AQ_RC_EBUSY'?
     101 |                         if (hw->adminq.sq_last_status != ICE_AQ_RC_EBUSY ||
         |                                                          ^~~~~~~~~~~~~~~
         |                                                          LIBIE_AQ_RC_EBUSY
   drivers/net/ethernet/intel/ice/ice_nvm.c:101:58: note: each undeclared identifier is reported only once for each function it appears in


vim +101 drivers/net/ethernet/intel/ice/ice_nvm.c

    48	
    49	/**
    50	 * ice_read_flat_nvm - Read portion of NVM by flat offset
    51	 * @hw: pointer to the HW struct
    52	 * @offset: offset from beginning of NVM
    53	 * @length: (in) number of bytes to read; (out) number of bytes actually read
    54	 * @data: buffer to return data in (sized to fit the specified length)
    55	 * @read_shadow_ram: if true, read from shadow RAM instead of NVM
    56	 *
    57	 * Reads a portion of the NVM, as a flat memory space. This function correctly
    58	 * breaks read requests across Shadow RAM sectors and ensures that no single
    59	 * read request exceeds the maximum 4KB read for a single AdminQ command.
    60	 *
    61	 * Returns a status code on failure. Note that the data pointer may be
    62	 * partially updated if some reads succeed before a failure.
    63	 */
    64	int
    65	ice_read_flat_nvm(struct ice_hw *hw, u32 offset, u32 *length, u8 *data,
    66			  bool read_shadow_ram)
    67	{
    68		u32 inlen = *length;
    69		u32 bytes_read = 0;
    70		int retry_cnt = 0;
    71		bool last_cmd;
    72		int status;
    73	
    74		*length = 0;
    75	
    76		/* Verify the length of the read if this is for the Shadow RAM */
    77		if (read_shadow_ram && ((offset + inlen) > (hw->flash.sr_words * 2u))) {
    78			ice_debug(hw, ICE_DBG_NVM, "NVM error: requested offset is beyond Shadow RAM limit\n");
    79			return -EINVAL;
    80		}
    81	
    82		do {
    83			u32 read_size, sector_offset;
    84	
    85			/* ice_aq_read_nvm cannot read more than 4KB at a time.
    86			 * Additionally, a read from the Shadow RAM may not cross over
    87			 * a sector boundary. Conveniently, the sector size is also
    88			 * 4KB.
    89			 */
    90			sector_offset = offset % ICE_AQ_MAX_BUF_LEN;
    91			read_size = min_t(u32, ICE_AQ_MAX_BUF_LEN - sector_offset,
    92					  inlen - bytes_read);
    93	
    94			last_cmd = !(bytes_read + read_size < inlen);
    95	
    96			status = ice_aq_read_nvm(hw, ICE_AQC_NVM_START_POINT,
    97						 offset, read_size,
    98						 data + bytes_read, last_cmd,
    99						 read_shadow_ram, NULL);
   100			if (status) {
 > 101				if (hw->adminq.sq_last_status != ICE_AQ_RC_EBUSY ||
   102				    retry_cnt > ICE_SQ_SEND_MAX_EXECUTE)
   103					break;
   104				ice_debug(hw, ICE_DBG_NVM,
   105					  "NVM read EBUSY error, retry %d\n",
   106					  retry_cnt + 1);
   107				last_cmd = false;
   108				ice_release_nvm(hw);
   109				msleep(ICE_SQ_SEND_DELAY_TIME_MS);
   110				status = ice_acquire_nvm(hw, ICE_RES_READ);
   111				if (status)
   112					break;
   113				retry_cnt++;
   114			} else {
   115				bytes_read += read_size;
   116				offset += read_size;
   117				retry_cnt = 0;
   118			}
   119		} while (!last_cmd);
   120	
   121		*length = bytes_read;
   122		return status;
   123	}
   124	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki