package/kernel/mac80211/patches/160-ath10k-search-all-IEs-for-variant-before-falling-back.patch

   1 From: Thomas Hebb <tommyhebb@gmail.com>
   2 Subject: [PATCH] ath10k: search all IEs for variant before falling back
   3 Date: Wed, 21 Feb 2018 11:43:39 -0500
   4
   5 commit f2593cb1b291 ("ath10k: Search SMBIOS for OEM board file
   6 extension") added a feature to ath10k that allows Board Data File
   7 (BDF) conflicts between multiple devices that use the same device IDs
   8 but have different calibration requirements to be resolved by allowing
   9 a "variant" string to be stored in SMBIOS [and later device tree, added
  10 by commit d06f26c5c8a4 ("ath10k: search DT for qcom,ath10k-calibration-
  11 variant")] that gets appended to the ID stored in board-2.bin.
  12
  13 This original patch had a regression, however. Namely that devices with
  14 a variant present in SMBIOS that didn't need custom BDFs could no longer
  15 find the default BDF, which has no variant appended. The patch was
  16 reverted and re-applied with a fix for this issue in commit 1657b8f84ed9
  17 ("search SMBIOS for OEM board file extension").
  18
  19 But the fix to fall back to a default BDF introduced another issue: the
  20 driver currently parses IEs in board-2.bin one by one, and for each one
  21 it first checks to see if it matches the ID with the variant appended.
  22 If it doesn't, it checks to see if it matches the "fallback" ID with no
  23 variant. If a matching BDF is found at any point during this search, the
  24 search is terminated and that BDF is used. The issue is that it's very
  25 possible (and is currently the case for board-2.bin files present in the
  26 ath10k-firmware repository) for the default BDF to occur in an earlier
  27 IE than the variant-specific BDF. In this case, the current code will
  28 happily choose the default BDF even though a better-matching BDF is
  29 present later in the file.
  30
  31 This patch fixes the issue by first searching the entire file for the ID
  32 with variant, and searching for the fallback ID only if that search
  33 fails. It also includes some code cleanup in the area, as
  34 ath10k_core_fetch_board_data_api_n() no longer does its own string
  35 mangling to remove the variant from an ID, instead leaving that job to a
  36 new flag passed to ath10k_core_create_board_name().
  37
  38 I've tested this patch on a QCA4019 and verified that the driver behaves
  39 correctly for 1) both fallback and variant BDFs present, 2) only fallback
  40 BDF present, and 3) no matching BDFs present.
  41
  42 Fixes: 1657b8f84ed9 ("ath10k: search SMBIOS for OEM board file extension")
  43 Signed-off-by: Thomas Hebb <tommyhebb@gmail.com>
  44 ---
  45  drivers/net/wireless/ath/ath10k/core.c | 134 ++++++++++++++++++---------------
  46  1 file changed, 72 insertions(+), 62 deletions(-)
  47
  48 --- a/drivers/net/wireless/ath/ath10k/core.c
  49 +++ b/drivers/net/wireless/ath/ath10k/core.c
  50 @@ -1129,14 +1129,61 @@ out:
  51         return ret;
  52  }
  53
  54 +static int ath10k_core_search_bd(struct ath10k *ar,
  55 +                                const char *boardname,
  56 +                                const u8 *data,
  57 +                                size_t len)
  58 +{
  59 +       size_t ie_len;
  60 +       struct ath10k_fw_ie *hdr;
  61 +       int ret = -ENOENT, ie_id;
  62 +
  63 +       while (len > sizeof(struct ath10k_fw_ie)) {
  64 +               hdr = (struct ath10k_fw_ie *)data;
  65 +               ie_id = le32_to_cpu(hdr->id);
  66 +               ie_len = le32_to_cpu(hdr->len);
  67 +
  68 +               len -= sizeof(*hdr);
  69 +               data = hdr->data;
  70 +
  71 +               if (len < ALIGN(ie_len, 4)) {
  72 +                       ath10k_err(ar, "invalid length for board ie_id %d ie_len %zu len %zu\n",
  73 +                                  ie_id, ie_len, len);
  74 +                       return -EINVAL;
  75 +               }
  76 +
  77 +               switch (ie_id) {
  78 +               case ATH10K_BD_IE_BOARD:
  79 +                       ret = ath10k_core_parse_bd_ie_board(ar, data, ie_len,
  80 +                                                           boardname);
  81 +                       if (ret == -ENOENT)
  82 +                               /* no match found, continue */
  83 +                               break;
  84 +
  85 +                       /* either found or error, so stop searching */
  86 +                       goto out;
  87 +               }
  88 +
  89 +               /* jump over the padding */
  90 +               ie_len = ALIGN(ie_len, 4);
  91 +
  92 +               len -= ie_len;
  93 +               data += ie_len;
  94 +       }
  95 +
  96 +out:
  97 +       /* return result of parse_bd_ie_board() or -ENOENT */
  98 +       return ret;
  99 +}
 100 +
 101  static int ath10k_core_fetch_board_data_api_n(struct ath10k *ar,
 102                                               const char *boardname,
 103 +                                             const char *fallback_boardname,
 104                                               const char *filename)
 105  {
 106 -       size_t len, magic_len, ie_len;
 107 -       struct ath10k_fw_ie *hdr;
 108 +       size_t len, magic_len;
 109         const u8 *data;
 110 -       int ret, ie_id;
 111 +       int ret;
 112
 113         ar->normal_mode_fw.board = ath10k_fetch_fw_file(ar,
 114                                                         ar->hw_params.fw.dir,
 115 @@ -1174,69 +1221,23 @@ static int ath10k_core_fetch_board_data_
 116         data += magic_len;
 117         len -= magic_len;
 118
 119 -       while (len > sizeof(struct ath10k_fw_ie)) {
 120 -               hdr = (struct ath10k_fw_ie *)data;
 121 -               ie_id = le32_to_cpu(hdr->id);
 122 -               ie_len = le32_to_cpu(hdr->len);
 123 -
 124 -               len -= sizeof(*hdr);
 125 -               data = hdr->data;
 126 -
 127 -               if (len < ALIGN(ie_len, 4)) {
 128 -                       ath10k_err(ar, "invalid length for board ie_id %d ie_len %zu len %zu\n",
 129 -                                  ie_id, ie_len, len);
 130 -                       ret = -EINVAL;
 131 -                       goto err;
 132 -               }
 133 +       /* attempt to find boardname in the IE list */
 134 +       ret = ath10k_core_search_bd(ar, boardname, data, len);
 135
 136 -               switch (ie_id) {
 137 -               case ATH10K_BD_IE_BOARD:
 138 -                       ret = ath10k_core_parse_bd_ie_board(ar, data, ie_len,
 139 -                                                           boardname);
 140 -                       if (ret == -ENOENT && ar->id.bdf_ext[0] != '\0') {
 141 -                               /* try default bdf if variant was not found */
 142 -                               char *s, *v = ",variant=";
 143 -                               char boardname2[100];
 144 -
 145 -                               strlcpy(boardname2, boardname,
 146 -                                       sizeof(boardname2));
 147 -
 148 -                               s = strstr(boardname2, v);
 149 -                               if (s)
 150 -                                       *s = '\0';  /* strip ",variant=%s" */
 151 -
 152 -                               ret = ath10k_core_parse_bd_ie_board(ar, data,
 153 -                                                                   ie_len,
 154 -                                                                   boardname2);
 155 -                       }
 156 +       /* if we didn't find it and have a fallback name, try that */
 157 +       if (ret == -ENOENT && fallback_boardname)
 158 +               ret = ath10k_core_search_bd(ar, fallback_boardname, data, len);
 159
 160 -                       if (ret == -ENOENT)
 161 -                               /* no match found, continue */
 162 -                               break;
 163 -                       else if (ret)
 164 -                               /* there was an error, bail out */
 165 -                               goto err;
 166 -
 167 -                       /* board data found */
 168 -                       goto out;
 169 -               }
 170 -
 171 -               /* jump over the padding */
 172 -               ie_len = ALIGN(ie_len, 4);
 173 -
 174 -               len -= ie_len;
 175 -               data += ie_len;
 176 -       }
 177 -
 178 -out:
 179 -       if (!ar->normal_mode_fw.board_data || !ar->normal_mode_fw.board_len) {
 180 +       if (ret == -ENOENT) {
 181                 ath10k_err(ar,
 182                            "failed to fetch board data for %s from %s/%s\n",
 183                            boardname, ar->hw_params.fw.dir, filename);
 184                 ret = -ENODATA;
 185 -               goto err;
 186         }
 187
 188 +       if (ret)
 189 +               goto err;
 190 +
 191         return 0;
 192
 193  err:
 194 @@ -1245,12 +1246,12 @@ err:
 195  }
 196
 197  static int ath10k_core_create_board_name(struct ath10k *ar, char *name,
 198 -                                        size_t name_len)
 199 +                                        size_t name_len, bool with_variant)
 200  {
 201         /* strlen(',variant=') + strlen(ar->id.bdf_ext) */
 202         char variant[9 + ATH10K_SMBIOS_BDF_EXT_STR_LENGTH] = { 0 };
 203
 204 -       if (ar->id.bdf_ext[0] != '\0')
 205 +       if (with_variant && ar->id.bdf_ext[0] != '\0')
 206                 scnprintf(variant, sizeof(variant), ",variant=%s",
 207                           ar->id.bdf_ext);
 208
 209 @@ -1276,17 +1277,26 @@ out:
 210
 211  static int ath10k_core_fetch_board_file(struct ath10k *ar)
 212  {
 213 -       char boardname[100];
 214 +       char boardname[100], fallback_boardname[100];
 215         int ret;
 216
 217 -       ret = ath10k_core_create_board_name(ar, boardname, sizeof(boardname));
 218 +       ret = ath10k_core_create_board_name(ar, boardname,
 219 +                                           sizeof(boardname), true);
 220         if (ret) {
 221                 ath10k_err(ar, "failed to create board name: %d", ret);
 222                 return ret;
 223         }
 224
 225 +       ret = ath10k_core_create_board_name(ar, fallback_boardname,
 226 +                                           sizeof(boardname), false);
 227 +       if (ret) {
 228 +               ath10k_err(ar, "failed to create fallback board name: %d", ret);
 229 +               return ret;
 230 +       }
 231 +
 232         ar->bd_api = 2;
 233         ret = ath10k_core_fetch_board_data_api_n(ar, boardname,
 234 +                                                fallback_boardname,
 235                                                  ATH10K_BOARD_API2_FILE);
 236         if (!ret)
 237                 goto success;