[PATCH 1/9] dma: pl330: rip out broken, redundant ID probing
Vinod Koul
vinod.koul at intel.com
Wed Jun 12 15:31:30 EST 2013
On Mon, Jun 10, 2013 at 07:34:37PM +0100, Will Deacon wrote:
> The PL330 driver probes the peripheral and primecell IDs of the device to
> make sure that it is indeed an AMBA PL330. However, it does this by
> making byte accesses to a device mapping of the word-aligned ID
> registers, which is either UNPREDICTABLE or generates an alignment fault
> (depending on the presence of the virtualisation extensions).
>
> Rather than fix this code, we can actually rip most of it out and let
> the AMBA bus driver correctly do the probing for us.
>
> Cc: Jassi Brar <jaswinder.singh at linaro.org>
> Cc: Vinod Koul <vinod.koul at intel.com>
> Signed-off-by: Will Deacon <will.deacon at arm.com>
Applied, thanks
--
~Vinod
> ---
> drivers/dma/pl330.c | 27 +++------------------------
> 1 file changed, 3 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 24e0754..22e2a8f 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -157,7 +157,6 @@ enum pl330_reqtype {
> #define PERIPH_REV_R0P0 0
> #define PERIPH_REV_R1P0 1
> #define PERIPH_REV_R1P1 2
> -#define PCELL_ID 0xff0
>
> #define CR0_PERIPH_REQ_SET (1 << 0)
> #define CR0_BOOT_EN_SET (1 << 1)
> @@ -193,8 +192,6 @@ enum pl330_reqtype {
> #define INTEG_CFG 0x0
> #define PERIPH_ID_VAL ((PART << 0) | (DESIGNER << 12))
>
> -#define PCELL_ID_VAL 0xb105f00d
> -
> #define PL330_STATE_STOPPED (1 << 0)
> #define PL330_STATE_EXECUTING (1 << 1)
> #define PL330_STATE_WFE (1 << 2)
> @@ -292,7 +289,6 @@ static unsigned cmd_line;
> /* Populated by the PL330 core driver for DMA API driver's info */
> struct pl330_config {
> u32 periph_id;
> - u32 pcell_id;
> #define DMAC_MODE_NS (1 << 0)
> unsigned int mode;
> unsigned int data_bus_width:10; /* In number of bits */
> @@ -650,19 +646,6 @@ static inline bool _manager_ns(struct pl330_thread *thrd)
> return (pl330->pinfo->pcfg.mode & DMAC_MODE_NS) ? true : false;
> }
>
> -static inline u32 get_id(struct pl330_info *pi, u32 off)
> -{
> - void __iomem *regs = pi->base;
> - u32 id = 0;
> -
> - id |= (readb(regs + off + 0x0) << 0);
> - id |= (readb(regs + off + 0x4) << 8);
> - id |= (readb(regs + off + 0x8) << 16);
> - id |= (readb(regs + off + 0xc) << 24);
> -
> - return id;
> -}
> -
> static inline u32 get_revision(u32 periph_id)
> {
> return (periph_id >> PERIPH_REV_SHIFT) & PERIPH_REV_MASK;
> @@ -1986,9 +1969,6 @@ static void read_dmac_config(struct pl330_info *pi)
> pi->pcfg.num_events = val;
>
> pi->pcfg.irq_ns = readl(regs + CR3);
> -
> - pi->pcfg.periph_id = get_id(pi, PERIPH_ID);
> - pi->pcfg.pcell_id = get_id(pi, PCELL_ID);
> }
>
> static inline void _reset_thread(struct pl330_thread *thrd)
> @@ -2098,10 +2078,8 @@ static int pl330_add(struct pl330_info *pi)
> regs = pi->base;
>
> /* Check if we can handle this DMAC */
> - if ((get_id(pi, PERIPH_ID) & 0xfffff) != PERIPH_ID_VAL
> - || get_id(pi, PCELL_ID) != PCELL_ID_VAL) {
> - dev_err(pi->dev, "PERIPH_ID 0x%x, PCELL_ID 0x%x !\n",
> - get_id(pi, PERIPH_ID), get_id(pi, PCELL_ID));
> + if ((pi->pcfg.periph_id & 0xfffff) != PERIPH_ID_VAL) {
> + dev_err(pi->dev, "PERIPH_ID 0x%x !\n", pi->pcfg.periph_id);
> return -EINVAL;
> }
>
> @@ -2922,6 +2900,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
> if (ret)
> return ret;
>
> + pi->pcfg.periph_id = adev->periphid;
> ret = pl330_add(pi);
> if (ret)
> goto probe_err1;
> --
> 1.8.2.2
>
--
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