SDM439平台出现部分机型SD卡不能识别mmc1: error -110 whilst initialising SD card【学习笔记】

SDM439平台出现部分机型SD卡不能识别mmc1: error -110 whilst initialising SD card

打印了如下的log：

 - ::02.699 <>[ 3079.000640] mmc1: data txfr (0x00100000) error: - after  ms
 - ::02.699 <>[ 3079.000652] sdhci: =========== REGISTER DUMP (mmc1)===========
 - ::02.699 <>[ 3079.000655] sdhci: Sys addr: 0x00000000 | Version:  0x00004d02
 - ::02.699 <>[ 3079.000658] sdhci: Blk size: 0x00004040 | Blk cnt:  0x00000001
 - ::02.699 <>[ 3079.000660] sdhci: Argument: 0x80ff3fff | Trn mode: 0x00000013
 - ::02.699 <>[ 3079.000663] sdhci: Present:  0x03f80206 | Host ctl: 0x0000001a
 - ::02.699 <>[ 3079.000665] sdhci: Power:    0x0000000d | Blk gap:  0x00000000
 - ::02.699 <>[ 3079.000667] sdhci: Wake-up:  0x00000000 | Clock:    0x00000007
 - ::02.699 <>[ 3079.000670] sdhci: Timeout:  0x00000001 | Int stat: 0x00000000
 - ::02.699 <>[ 3079.000672] sdhci: Int enab: 0x03ff900b | Sig enab: 0x03ff100b
 - ::02.699 <>[ 3079.000674] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000000
 - ::02.699 <>[ 3079.000677] sdhci: Caps:     0x362dc8b2 | Caps_1:   0x00008007
 - ::02.699 <>[ 3079.000679] sdhci: Cmd:      0x0000063a | Max curr: 0x00000000
 - ::02.699 <>[ 3079.000682] sdhci: Resp :   0x5b590000 | Resp :   0x00000900
 - ::02.699 <>[ 3079.000684] sdhci: Resp :   0x0a404012 | Resp :   0x76b27f80
 - ::02.699 <>[ 3079.000686] sdhci: Host ctl2: 0x00000008
 - ::02.699 <>[ 3079.000689] sdhci: ADMA Err: 0x00000003 | ADMA Ptr: 0x00000000f5c9820c
 - ::02.699 <>[ 3079.000695] ----------- VENDOR REGISTER DUMP -----------
 - ::02.699 <>[ 3079.000699] Data cnt: 0x00000040 | Fifo cnt: 0x00000040 | Int sts: 0x000c0000
 - ::02.700 <>[ 3079.000702] DLL cfg:  0x6002642c | DLL sts:  0x00000000 | SDCC ver: 0x1000004d
 - ::02.700 <>[ 3079.000705] Vndr func: 0x00018a9c | Vndr adma err : addr0: 0x000a3f80 addr1: 0x00000000
 - ::02.700 <>[ 3079.000707] Vndr func2: 0xfa8018a8
 - ::02.700 <>[ 3079.000746]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000748]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000751]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000753]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000755]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000758]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000760]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000763]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000766]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000768]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000770]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000773]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000776]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000778]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000781]  Test bus[ to ]: 0x00000000 0x00000000 0x00000000 0x00000000
 - ::02.700 <>[ 3079.000785] mmc1: clk:  clk-gated:  claimer: kworker/: pwr:  host->irq =
 - ::02.700 <>[ 3079.000788] mmc1: rpmstatus[pltfm](runtime-suspend:usage_count:disable_depth)(::)
 - ::02.700 <>[ 3079.000790] sdhci: ===========================================
 - ::02.765 <>[ 3079.066337] [FTS][Info]TP Ready, Device ID = 0x54
 - ::03.559 <>[ 3079.862932] mmc1: mmc_sd_init_card() failure (err = -)
 - ::03.559 <>[ 3079.862944] mmc1: error - whilst initialising SD card

从log上分析出错的应该是在SD的初始化的阶段有问题(mmc1: error -110 whilst initialising SD card)。有可能是SD卡在上电的时候出现电源还没有稳定，需要增大上电等待的延迟,延迟的时间自己设定。代码修改如下:

 diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
 index eb9ff36..7842f45
 --- a/drivers/mmc/core/core.c
 +++ b/drivers/mmc/core/core.c
 @@ -, +, @@ void mmc_power_up(struct mmc_host *host, u32 ocr) 

 host->ios.vdd = fls(ocr) - ;
 host->ios.power_mode = MMC_POWER_UP;
 +
 + printk(KERN_ERR"zhuangzebin:>>>>>%s-%d<<<<<<<\r\n",__func__,__LINE__);
 + dev_dbg(mmc_dev(host), "zhuangzebin mmc before init\n");
 /* Set initial state and call mmc_set_ios */
 mmc_set_initial_state(host); 

 @@ -, +, @@ void mmc_power_up(struct mmc_host *host, u32 ocr)
 * This delay should be sufficient to allow the power supply
 * to reach the minimum voltage.
 */
 - mmc_delay();
 + mmc_delay(); 

 mmc_pwrseq_post_power_on(host); 

 @@ -, +, @@ void mmc_power_up(struct mmc_host *host, u32 ocr)
 * This delay must be at least  clock sizes, or  ms, or the
 * time required to reach a stable voltage.
 */
 - mmc_delay();
 + mmc_delay(); 

 mmc_host_clk_release(host);
 +
 + mmc_delay();
 }

编译重新烧录固件，仍然有这个问题的存在，已经把延迟的时间增大了10倍，排除软件问题，后面找硬件分析，SD卡的一颗物料没有焊接。而且机器有拆过的痕迹，那颗物料刚好处于边缘的地方，有可能是拆卸的时候导致物料脱落，后面硬件把物料焊接上，可以识别到SD卡。