[PATCH, regression against -rc6] net/stmmac: fix one more regression from filter bins setting

[chenhc@lemote.com (陈华才)]

Hi, Arnd,

Maybe this patch is better?
http://www.spinics.net/lists/netdev/msg306413.html

Huacai
 
------------------ Original ------------------
From:  "Arnd Bergmann"<arnd@arndb.de>;
Date:  Sat, Nov 29, 2014 08:03 PM
To:  "David Miller"<davem@davemloft.net>;
Cc:  "netdev"<netdev@vger.kernel.org>; "khilman"<khilman@kernel.org>; "Huacai Chen"<chenhc@lemote.com>; "Giuseppe Cavallaro"<peppe.cavallaro@st.com>; "olof"<olof@lixom.net>; "linux-arm-kernel"<linux-arm-kernel@lists.infradead.org>;
Subject:  [PATCH, regression against -rc6] net/stmmac: fix one more regression from filter bins setting
 
Commit 571dcfde2371 ("stmmac: platform: fix default values of the filter
bins setting") tries to fix a regression in the stmmac driver, but instead
it also causes a new regression and makes all DT-based users of this
driver fail, as found by the automated ARM boot testing:

[    0.881667] Unable to handle kernel NULL pointer dereference at virtual address 00000048
[    0.889784] pgd = c0204000
[    0.892502] [00000048] *pgd=00000000
[    0.896090] Internal error: Oops: 805 [#1] SMP ARM
[    0.900874] Modules linked in:
[    0.903943] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc6-00150-g8891063 #1
[    0.911502] task: ee06c000 ti: ee070000 task.ti: ee070000
[    0.916899] PC is at stmmac_pltfr_probe+0x40/0x5d0
[    0.921689] LR is at devm_ioremap_nocache+0x54/0x74
[    0.926561] pc : [<c0642df8>]    lr : [<c0430508>]    psr: 80000153
[    0.926561] sp : ee071e50  ip : 00000000  fp : 00000000
[    0.938020] r10: c0c14f74  r9 : ee3ca2c0  r8 : ee101c10
[    0.943237] r7 : f00c0000  r6 : ee101c00  r5 : ee101c10  r4 : 00000000
[    0.949755] r3 : 00000001  r2 : 00000040  r1 : a0000153  r0 : f00c0000
[    0.956274] Flags: Nzcv  IRQs on  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
[    0.963658] Control: 10c5387d  Table: 4020406a  DAC: 00000015
[    0.969395] Process swapper/0 (pid: 1, stack limit = 0xee070248)
[    0.975384] Stack: (0xee071e50 to 0xee072000)
[    0.979738] 1e40:                                     c0d83aa0 ee101c10 c0cfc030 fffffdfb
[    0.987906] 1e60: 00000000 ee3ca2c0 c0c14f74 c056c6d0 c056c68c c0d83aa0 ee101c10 00000000
[    0.996075] 1e80: c0cfc030 c056af54 ee101c10 c0cfc030 ee101c44 c0cf15f8 c0c616a0 c056b158
[    1.004243] 1ea0: 00000000 c0cfc030 c056b0cc c0569514 ee01675c ee0d86b4 c0cfc030 ee3c9300
[    1.012412] 1ec0: 00000000 c056a77c c0ad7be0 ee071ef8 c0cfc030 c0cfc030 ee070000 c0be0ca8
[    1.020580] 1ee0: 00000000 c056b77c 00000000 c0c616a0 ee070000 c0be0cbc c0c616a0 c0208cb0
[    1.028750] 1f00: ee011900 c0d6c324 ee0b6600 c08a6748 00000000 00000000 00006a40 c034782c
[    1.036918] 1f20: 00000000 c0ca1aac 60000153 00000001 c0b9f598 ef7fcd9c ef7fcd99 c025ffa0
[    1.045087] 1f40: c0ae650c ef7fcda0 00000006 00000006 c0ca1a94 c0c50d44 00000006 c0c14f6c
[    1.053255] 1f60: c0d46a40 c0d46a40 000000ff c0c14f74 00000000 c0b9fda4 00000006 00000006
[    1.061423] 1f80: c0b9f598 9c041042 00000000 c089460c 00000000 00000000 00000000 00000000
[    1.069591] 1fa0: 00000000 c0894614 00000000 c020e878 00000000 00000000 00000000 00000000
[    1.077759] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    1.085926] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 18044434 8a444414
[    1.094113] [<c0642df8>] (stmmac_pltfr_probe) from [<c056c6d0>] (platform_drv_probe+0x44/0xa4)
[    1.102719] [<c056c6d0>] (platform_drv_probe) from [<c056af54>] (driver_probe_device+0x108/0x23c)
[    1.111582] [<c056af54>] (driver_probe_device) from [<c056b158>] (__driver_attach+0x8c/0x90)
[    1.120011] [<c056b158>] (__driver_attach) from [<c0569514>] (bus_for_each_dev+0x6c/0xa0)
[    1.128182] [<c0569514>] (bus_for_each_dev) from [<c056a77c>] (bus_add_driver+0x148/0x1f0)
[    1.136438] [<c056a77c>] (bus_add_driver) from [<c056b77c>] (driver_register+0x78/0xf8)
[    1.144434] [<c056b77c>] (driver_register) from [<c0be0cbc>] (stmmac_init+0x14/0x3c)
[    1.152176] [<c0be0cbc>] (stmmac_init) from [<c0208cb0>] (do_one_initcall+0x8c/0x1c4)
[    1.160004] [<c0208cb0>] (do_one_initcall) from [<c0b9fda4>] (kernel_init_freeable+0x13c/0x1dc)
[    1.168699] [<c0b9fda4>] (kernel_init_freeable) from [<c0894614>] (kernel_init+0x8/0xe8)
[    1.176785] [<c0894614>] (kernel_init) from [<c020e878>] (ret_from_fork+0x14/0x3c)
[    1.184348] Code: 8a0000fe e5964064 e3a02040 e3a03001 (e5842048)
[    1.190501] ---[ end trace 724411f6ae142767 ]---
[    1.195158] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

Where the original patch left out the non-DT probe method, the fix that
was merged for -rc7 instead broke the DT path by dereferencing a NULL
pointer.

This patch reverts the broken fix and tries to put the initialization
for multicast_filter_bins/unicast_filter_entries in the right place,
which prevents non-DT users from overriding the defaults as a side
effect, as before. Alternatively, one could change all instances of
the platform_data definition to set the values themselves, but it's
probably safer to do that as a follow-up.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 571dcfde2371 ("stmmac: platform: fix default values of the filter bins setting")
Link: http://arm-soc.lixom.net/bootlogs/mainline/v3.18-rc6-150-g8891063/cubie2-arm-multi_v7_defconfig.html
---
I've sent this off to the build bots, but it will probably take some more
time before it's been tested on all the ARM machines and I might not be
there to see the results, so I'm sending it out now for review. I will
reply once I am sure the problem is fixed.

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 5b0da3986216..94c3cefaa2c3 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -177,6 +177,12 @@ static int stmmac_probe_config_dt(struct platform_device *pdev,
 	 */
 	plat->maxmtu = JUMBO_LEN;
 
+	/* Set default value for multicast hash bins */
+	plat->multicast_filter_bins = HASH_TABLE_SIZE;
+
+	/* Set default value for unicast filter entries */
+	plat->unicast_filter_entries = 1;
+
 	/*
 	 * Currently only the properties needed on SPEAr600
 	 * are provided. All other properties should be added
@@ -264,13 +270,6 @@ static int stmmac_pltfr_probe(struct platform_device *pdev)
 	 return PTR_ERR(addr);
 
 	plat_dat = dev_get_platdata(&pdev->dev);
-
-	/* Set default value for multicast hash bins */
-	plat_dat->multicast_filter_bins = HASH_TABLE_SIZE;
-
-	/* Set default value for unicast filter entries */
-	plat_dat->unicast_filter_entries = 1;
-
 	if (pdev->dev.of_node) {
 	 if (!plat_dat)
 	 plat_dat = devm_kzalloc(&pdev->dev,
@@ -286,6 +285,12 @@ static int stmmac_pltfr_probe(struct platform_device *pdev)
 	 pr_err("%s: main dt probe failed", __func__);
 	 return ret;
 	 }
+	} else {
+	 /* Set default value for multicast hash bins */
+	 plat_dat->multicast_filter_bins = HASH_TABLE_SIZE;
+
+	 /* Set default value for unicast filter entries */
+	 plat_dat->unicast_filter_entries = 1;
 	}
 
 	/* Custom setup (if needed) */