Re: [PATCH 2/5] coresight: etmv4: Fix ETMv4x peripheral ID table

From: Mathieu Poirier
Date: Tue May 31 2016 - 13:45:45 EST


On 31 May 2016 at 05:57, Suzuki K Poulose <suzuki.poulose@xxxxxxx> wrote:
> This patch cleans up the peripheral id table for different ETMv4
> implementations.
>
> As per Cortex-A53 TRM, the ETM has following id values:
>
> Peripheral ID0 0x5D 0xFE0
> Peripheral ID1 0xB9 0xFE4
> Peripheral ID2 0x4B 0xFE8
> Peripheral ID3 0x00 0xFEC
>
> where, PID2: has the following format:
>
> [7:4] Revision
> [3] JEDEC 0b1 res1. Indicates a JEP106 identity code is used
> [2:0] DES_1 0b011 ARM Limited. This is bits[6:4] of JEP106 ID code
>
> The existing table entry checks only the bits [1:0], which is not
> sufficient enough. Fix it to match bits [3:0], just like the other
> entries do. While at it, correct the comment for A57 and the A53 entry.
>
> Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> ---
> drivers/hwtracing/coresight/coresight-etm4x.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index 462f0dc..88947f3 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -815,12 +815,12 @@ err_arch_supported:
> }
>
> static struct amba_id etm4_ids[] = {
> - { /* ETM 4.0 - Qualcomm */
> - .id = 0x0003b95d,
> - .mask = 0x0003ffff,
> + { /* ETM 4.0 - Cortex-A53 */
> + .id = 0x000bb95d,
> + .mask = 0x000fffff,
> .data = "ETM 4.0",
> },
> - { /* ETM 4.0 - Juno board */
> + { /* ETM 4.0 - Cortex-A57 */
> .id = 0x000bb95e,
> .mask = 0x000fffff,
> .data = "ETM 4.0",
> --
> 1.9.1
>

I'll apply this to my next tree but since it doesn't cause a core dump
or prevent the kernel from booting, I don't think it deserves to be in
-rc2.

Thanks,
Mathieu