答复: [PATCH] hw/net: cadence_gem: fix: type2_compare_x_word_0 error

[andrew Yuan]

OK，I will send another patch for the missing logic for the DISABLE_MASK bit;

 

 

发件人: Edgar E. Iglesias <edgar.iglesias@gmail.com>
发送时间: 2024年6月6日 19:04
收件人: andrew Yuan <andrew.yuan@jaguarmicro.com>
抄送: luc.michel@amd.com; alistair@alistair23.me; peter.maydell@linaro.org; jasowang@redhat.com; qemu-arm@nongnu.org; qemu-devel@nongnu.org
主题: Re: [PATCH] hw/net: cadence_gem: fix: type2_compare_x_word_0 error

 

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On Thu, Jun 6, 2024 at 12:00 PM Andrew.Yuan <andrew.yuan@jaguarmicro.com> wrote:

        In the Cadence IP for Gigabit Ethernet MAC Part Number: IP7014 IP Rev: R1p12 - Doc Rev: 1.3 User Guide, the specification for the type2_compare_x_word_0 register is as follows:
        The byte stored in bits [23:16] is compared against the byte in the received frame from the selected offset+0, and the byte stored in bits [31:24] is compared against the byte in
        the received frame from the selected offset+1.

        However, there is an implementation error in the cadence_gem model in qemu：
        the byte stored in bits [31:24] is compared against the byte in the received frame from the selected offset+0

        Now, the error code is as follows:
        rx_cmp = rxbuf_ptr[offset] << 8 | rxbuf_ptr[offset];

        and needs to be corrected to：
        rx_cmp = rxbuf_ptr[offset + 1] << 8 | rxbuf_ptr[offset];

Signed-off-by: Andrew.Yuan <andrew.yuan@jaguarmicro.com>

 

 

LGTM:

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>

 

At some point it would be nice to add the missing logic for the DISABLE_MASK bit that

extends the compare range from 16 to 32-bits.

 

Cheers,

Edgar 

 

 

---
 hw/net/cadence_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index ec7bf562e5..9c73ded0d3 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -946,7 +946,7 @@ static int get_queue_from_screen(CadenceGEMState *s, uint8_t *rxbuf_ptr,
                 break;
             }

-            rx_cmp = rxbuf_ptr[offset] << 8 | rxbuf_ptr[offset];
+            rx_cmp = rxbuf_ptr[offset + 1] << 8 | rxbuf_ptr[offset];
             mask = FIELD_EX32(cr0, TYPE2_COMPARE_0_WORD_0, MASK_VALUE);
             compare = FIELD_EX32(cr0, TYPE2_COMPARE_0_WORD_0, COMPARE_VALUE);

--
2.37.0.windows.1