RE: [PATCH][v4] sata_fsl: add workaround for data length mismatchon freescale V2 controller

From: Xie Shaohui-B21989
Date: Mon Oct 15 2012 - 03:52:09 EST


Hi,

Any comment for this patch? It's been over a month...

Best Regards,
Shaohui Xie
> -----Original Message-----
> From: Xie Shaohui-B21989
> Sent: Tuesday, September 11, 2012 10:49 AM
> To: jgarzik@xxxxxxxxx; linux-ide@xxxxxxxxxxxxxxx
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Xie
> Shaohui-B21989; Bhartiya Anju-B07263
> Subject: [PATCH][v4] sata_fsl: add workaround for data length mismatch on
> freescale V2 controller
>
> The freescale V2 SATA controller checks if the received data length
> matches the programmed length 'ttl', if not, it assumes that this is an
> error.
> In ATAPI, the 'ttl' is based on max allocation length and not the actual
> data transfer length, controller will raise 'DLM' (Data length Mismatch)
> error bit in Hstatus register. Along with 'DLM', DE (Device error) and FE
> (fatal Error) bits are also set in Hstatus register, 'E' (Internal Error)
> bit is set in Serror register and CE (Command Error) and DE (Device error)
> registers have the corresponding bit set. In this condition, we need to
> clear errors in following way: in the service routine, based on 'DLM'
> flag, HCONTROL[27] operation clears Hstatus, CE and DE registers, clear
> Serror register.
>
> Signed-off-by: Shaohui Xie <Shaohui.Xie@xxxxxxxxxxxxx>
> Signed-off-by: Anju Bhartiya <Anju.Bhartiya@xxxxxxxxxxxxx>
> ---
> changes for v4:
> 1. put HCONTROL_CLEAR_ERROR to enum and rename it as CLEAR_ERROR;
>
> changes for v3:
> 1. not using uppercase for variable names; 2. remove unnecessary parens;
>
> changes for v2:
> 1. remove the using of quirk;
> 2. wrap errata codes in condition;
>
>
> drivers/ata/sata_fsl.c | 39 +++++++++++++++++++++++++++++++++++----
> 1 files changed, 35 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c index
> d6577b9..124b2c1 100644
> --- a/drivers/ata/sata_fsl.c
> +++ b/drivers/ata/sata_fsl.c
> @@ -123,6 +123,7 @@ enum {
> ONLINE = (1 << 31),
> GOING_OFFLINE = (1 << 30),
> BIST_ERR = (1 << 29),
> + CLEAR_ERROR = (1 << 27),
>
> FATAL_ERR_HC_MASTER_ERR = (1 << 18),
> FATAL_ERR_PARITY_ERR_TX = (1 << 17),
> @@ -143,6 +144,7 @@ enum {
> FATAL_ERR_CRC_ERR_RX |
> FATAL_ERR_FIFO_OVRFL_TX | FATAL_ERR_FIFO_OVRFL_RX,
>
> + INT_ON_DATA_LENGTH_MISMATCH = (1 << 12),
> INT_ON_FATAL_ERR = (1 << 5),
> INT_ON_PHYRDY_CHG = (1 << 4),
>
> @@ -1181,25 +1183,54 @@ static void sata_fsl_host_intr(struct ata_port
> *ap)
> u32 hstatus, done_mask = 0;
> struct ata_queued_cmd *qc;
> u32 SError;
> + u32 tag;
> + u32 status_mask = INT_ON_ERROR;
>
> hstatus = ioread32(hcr_base + HSTATUS);
>
> sata_fsl_scr_read(&ap->link, SCR_ERROR, &SError);
>
> + /* Read command completed register */
> + done_mask = ioread32(hcr_base + CC);
> +
> + /* Workaround for data length mismatch errata */
> + if (unlikely(hstatus & INT_ON_DATA_LENGTH_MISMATCH)) {
> + for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
> + qc = ata_qc_from_tag(ap, tag);
> + if (qc && ata_is_atapi(qc->tf.protocol)) {
> + u32 hcontrol;
> + /* Set HControl[27] to clear error registers */
> + hcontrol = ioread32(hcr_base + HCONTROL);
> + iowrite32(hcontrol | CLEAR_ERROR,
> + hcr_base + HCONTROL);
> +
> + /* Clear HControl[27] */
> + iowrite32(hcontrol & ~CLEAR_ERROR,
> + hcr_base + HCONTROL);
> +
> + /* Clear SError[E] bit */
> + sata_fsl_scr_write(&ap->link, SCR_ERROR,
> + SError);
> +
> + /* Ignore fatal error and device error */
> + status_mask &= ~(INT_ON_SINGL_DEVICE_ERR
> + | INT_ON_FATAL_ERR);
> + break;
> + }
> + }
> + }
> +
> if (unlikely(SError & 0xFFFF0000)) {
> DPRINTK("serror @host_intr : 0x%x\n", SError);
> sata_fsl_error_intr(ap);
> }
>
> - if (unlikely(hstatus & INT_ON_ERROR)) {
> + if (unlikely(hstatus & status_mask)) {
> DPRINTK("error interrupt!!\n");
> sata_fsl_error_intr(ap);
> return;
> }
>
> - /* Read command completed register */
> - done_mask = ioread32(hcr_base + CC);
> -
> VPRINTK("Status of all queues :\n");
> VPRINTK("done_mask/CC = 0x%x, CA = 0x%x,
> CE=0x%x,CQ=0x%x,apqa=0x%x\n",
> done_mask,
> --
> 1.6.4


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