target/linux/mvebu/patches-3.10/0140-mtd-nand-pxa3xx-Use-a-completion-to-signal-device-re.patch

   1 From b5289e9cb18e6c254e13826e6bcfbfe95b819d77 Mon Sep 17 00:00:00 2001
   2 From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
   3 Date: Thu, 14 Nov 2013 18:25:26 -0300
   4 Subject: [PATCH 140/203] mtd: nand: pxa3xx: Use a completion to signal device
   5  ready
   6
   7 The expected behavior of the waitfunc() NAND chip call is to wait
   8 for the device to be READY (this is a standard chip line).
   9 However, the current implementation does almost nothing, which opens
  10 the possibility of issuing a command to a non-ready device.
  11
  12 Fix this by adding a new completion to wait for the ready event to arrive.
  13
  14 Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
  15 Tested-by: Daniel Mack <zonque@gmail.com>
  16 Signed-off-by: Brian Norris <computersforpeace@gmail.com>
  17 ---
  18  drivers/mtd/nand/pxa3xx_nand.c | 38 ++++++++++++++++++++++++--------------
  19  1 file changed, 24 insertions(+), 14 deletions(-)
  20
  21 --- a/drivers/mtd/nand/pxa3xx_nand.c
  22 +++ b/drivers/mtd/nand/pxa3xx_nand.c
  23 @@ -37,6 +37,7 @@
  24
  25  #include <linux/platform_data/mtd-nand-pxa3xx.h>
  26
  27 +#define NAND_DEV_READY_TIMEOUT  50
  28  #define        CHIP_DELAY_TIMEOUT      (2 * HZ/10)
  29  #define NAND_STOP_DELAY                (2 * HZ/50)
  30  #define PAGE_CHUNK_SIZE                (2048)
  31 @@ -168,7 +169,7 @@ struct pxa3xx_nand_info {
  32         struct clk              *clk;
  33         void __iomem            *mmio_base;
  34         unsigned long           mmio_phys;
  35 -       struct completion       cmd_complete;
  36 +       struct completion       cmd_complete, dev_ready;
  37
  38         unsigned int            buf_start;
  39         unsigned int            buf_count;
  40 @@ -198,7 +199,7 @@ struct pxa3xx_nand_info {
  41         int                     use_ecc;        /* use HW ECC ? */
  42         int                     use_dma;        /* use DMA ? */
  43         int                     use_spare;      /* use spare ? */
  44 -       int                     is_ready;
  45 +       int                     need_wait;
  46
  47         unsigned int            fifo_size;      /* max. data size in the FIFO */
  48         unsigned int            data_size;      /* data to be read from FIFO */
  49 @@ -480,7 +481,7 @@ static void start_data_dma(struct pxa3xx
  50  static irqreturn_t pxa3xx_nand_irq(int irq, void *devid)
  51  {
  52         struct pxa3xx_nand_info *info = devid;
  53 -       unsigned int status, is_completed = 0;
  54 +       unsigned int status, is_completed = 0, is_ready = 0;
  55         unsigned int ready, cmd_done;
  56
  57         if (info->cs == 0) {
  58 @@ -516,8 +517,8 @@ static irqreturn_t pxa3xx_nand_irq(int i
  59                 is_completed = 1;
  60         }
  61         if (status & ready) {
  62 -               info->is_ready = 1;
  63                 info->state = STATE_READY;
  64 +               is_ready = 1;
  65         }
  66
  67         if (status & NDSR_WRCMDREQ) {
  68 @@ -546,6 +547,8 @@ static irqreturn_t pxa3xx_nand_irq(int i
  69         nand_writel(info, NDSR, status);
  70         if (is_completed)
  71                 complete(&info->cmd_complete);
  72 +       if (is_ready)
  73 +               complete(&info->dev_ready);
  74  NORMAL_IRQ_EXIT:
  75         return IRQ_HANDLED;
  76  }
  77 @@ -576,7 +579,6 @@ static int prepare_command_pool(struct p
  78         info->oob_size          = 0;
  79         info->use_ecc           = 0;
  80         info->use_spare         = 1;
  81 -       info->is_ready          = 0;
  82         info->retcode           = ERR_NONE;
  83         if (info->cs != 0)
  84                 info->ndcb0 = NDCB0_CSEL;
  85 @@ -749,6 +751,8 @@ static void pxa3xx_nand_cmdfunc(struct m
  86         exec_cmd = prepare_command_pool(info, command, column, page_addr);
  87         if (exec_cmd) {
  88                 init_completion(&info->cmd_complete);
  89 +               init_completion(&info->dev_ready);
  90 +               info->need_wait = 1;
  91                 pxa3xx_nand_start(info);
  92
  93                 ret = wait_for_completion_timeout(&info->cmd_complete,
  94 @@ -863,21 +867,27 @@ static int pxa3xx_nand_waitfunc(struct m
  95  {
  96         struct pxa3xx_nand_host *host = mtd->priv;
  97         struct pxa3xx_nand_info *info = host->info_data;
  98 +       int ret;
  99 +
 100 +       if (info->need_wait) {
 101 +               ret = wait_for_completion_timeout(&info->dev_ready,
 102 +                               CHIP_DELAY_TIMEOUT);
 103 +               info->need_wait = 0;
 104 +               if (!ret) {
 105 +                       dev_err(&info->pdev->dev, "Ready time out!!!\n");
 106 +                       return NAND_STATUS_FAIL;
 107 +               }
 108 +       }
 109
 110         /* pxa3xx_nand_send_command has waited for command complete */
 111         if (this->state == FL_WRITING || this->state == FL_ERASING) {
 112                 if (info->retcode == ERR_NONE)
 113                         return 0;
 114 -               else {
 115 -                       /*
 116 -                        * any error make it return 0x01 which will tell
 117 -                        * the caller the erase and write fail
 118 -                        */
 119 -                       return 0x01;
 120 -               }
 121 +               else
 122 +                       return NAND_STATUS_FAIL;
 123         }
 124
 125 -       return 0;
 126 +       return NAND_STATUS_READY;
 127  }
 128
 129  static int pxa3xx_nand_config_flash(struct pxa3xx_nand_info *info,
 130 @@ -1030,7 +1040,7 @@ static int pxa3xx_nand_sensing(struct px
 131                 return ret;
 132
 133         chip->cmdfunc(mtd, NAND_CMD_RESET, 0, 0);
 134 -       if (info->is_ready)
 135 +       if (!info->need_wait)
 136                 return 0;
 137
 138         return -ENODEV;