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Re: [PATCH 08/25] block/nvme: Simplify device reset
From: |
Philippe Mathieu-Daudé |
Subject: |
Re: [PATCH 08/25] block/nvme: Simplify device reset |
Date: |
Tue, 27 Oct 2020 16:53:31 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.1 |
On 10/27/20 3:58 PM, Keith Busch wrote:
> On Tue, Oct 27, 2020 at 02:55:30PM +0100, Philippe Mathieu-Daudé wrote:
>> Avoid multiple endianess conversion by using device endianess.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>> block/nvme.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/block/nvme.c b/block/nvme.c
>> index e95d59d3126..be14350f959 100644
>> --- a/block/nvme.c
>> +++ b/block/nvme.c
>> @@ -755,7 +755,7 @@ static int nvme_init(BlockDriverState *bs, const char
>> *device, int namespace,
>> timeout_ms = MIN(500 * NVME_CAP_TO(cap), 30000);
>>
>> /* Reset device to get a clean state. */
>> - regs->cc = cpu_to_le32(le32_to_cpu(regs->cc) & 0xFE);
>> + regs->cc &= const_le32(0xFE);
>
> This doesn't look right. The 'regs' is an MMIO address, correct? Memory
> mappings use the CPU native access.
cc is little-endian uint32_t.
on big-endian: const_le32(0xFE) = 0xfe000000;
so: regs->cc &= 0xfe000000.
Anyway this is an example of unproductive patch, as it makes
things more confuse to you. Let's ignore it.
- [PATCH 07/25] block/nvme: Trace queue pair creation/deletion, (continued)
[PATCH 12/25] block/nvme: Make nvme_init_queue() return boolean indicating error, Philippe Mathieu-Daudé, 2020/10/27
[PATCH 13/25] block/nvme: Introduce Completion Queue definitions, Philippe Mathieu-Daudé, 2020/10/27