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Date: Fri, 19 Jan 2024 20:13:25 -0800 (PST)
Subject:     Re: [PATCH v2] tty: hvc: Fix the RISC-V SBI driver for a refactoring
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From: Palmer Dabbelt <palmer@rivosinc.com>
To: anup@brainfault.org
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On Fri, 19 Jan 2024 19:59:11 PST (-0800), anup@brainfault.org wrote:
> On Sat, Jan 20, 2024 at 4:15 AM Palmer Dabbelt <palmer@rivosinc.com> wrote:
>>
>> From: Palmer Dabbelt <palmer@rivosinc.com>
>>
>> I missed the int->size_t refactoring in f32fcbedbe92 ("tty: hvc: convert
>> to u8 and size_t"), which causes the newly used ops in 88ead68e764c
>> ("tty: Add SBI debug console support to HVC SBI driver") to fail to
>> build due to a
>>
>> linux/drivers/tty/hvc/hvc_riscv_sbi.c:59:15: error: incompatible function pointer types initializing 'ssize_t (*)(uint32_t, const u8 *, size_t)' (aka 'long (*)(unsigned int, const unsigned char *, unsigned long)') with an expression of type 'int (uint32_t, const char *, int)' (aka 'int (unsigned int, const char *, int)') [-Wincompatible-function-pointer-types]
>>         .put_chars = hvc_sbi_dbcn_tty_put,
>>
>> Fixes: f32fcbedbe92 ("tty: hvc: convert to u8 and size_t")
>> Fixes: 88ead68e764c ("tty: Add SBI debug console support to HVC SBI driver")
>> Link: https://lore.kernel.org/r/20240119215612.20529-2-palmer@rivosinc.com
>> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
>> ---
>> Changes since v1 <20240119215612.20529-2-palmer@rivosinc.com>:
>> * Fix the return and arguments correctly.
>> * Also fix the hvc_sbi_dbcn_tty_{get,put}().
>> ---
>>  drivers/tty/hvc/hvc_riscv_sbi.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/tty/hvc/hvc_riscv_sbi.c b/drivers/tty/hvc/hvc_riscv_sbi.c
>> index 2f3571f17ecd..f8cd3310ef35 100644
>> --- a/drivers/tty/hvc/hvc_riscv_sbi.c
>> +++ b/drivers/tty/hvc/hvc_riscv_sbi.c
>> @@ -15,7 +15,7 @@
>>
>>  #include "hvc_console.h"
>>
>> -static int hvc_sbi_tty_put(uint32_t vtermno, const char *buf, int count)
>> +static ssize_t hvc_sbi_tty_put(uint32_t vtermno, const u8 *buf, size_t count)
>>  {
>>         int i;
>>
>> @@ -25,7 +25,7 @@ static int hvc_sbi_tty_put(uint32_t vtermno, const char *buf, int count)
>>         return i;
>>  }
>>
>> -static int hvc_sbi_tty_get(uint32_t vtermno, char *buf, int count)
>> +static ssize_t hvc_sbi_tty_get(uint32_t vtermno, u8 *buf, size_t count)
>
> The hvc_sbi_tty_put() and hvc_sbi_tty_get() functions are already
> updated in Linus's tree. We only need to fix hvc_sbi_dbcn_tty_put()
> and hvc_sbi_dbcn_tty_get()
>
> Please rebase this fix upon Linux-6.8-rc1 whenever that is available.

Ya, it's kind of clunky: we added functions at the same time as the 
refactoring, so there's no good clean tree to apply a patch to.  Right 
now I've actually got this bundled up into a merge, that's usually the 
worst option but it's about as good as I could come up with -- Linus 
still hasn't merged my part 2, so I'm going to send a part 3 once I get 
through the tests on my end.

So we'll see, likely tomorrow, and then I'll deal with the fallout after 
rc1...

>
>>  {
>>         int i, c;
>>
>> @@ -44,12 +44,12 @@ static const struct hv_ops hvc_sbi_v01_ops = {
>>         .put_chars = hvc_sbi_tty_put,
>>  };
>>
>> -static int hvc_sbi_dbcn_tty_put(uint32_t vtermno, const char *buf, int count)
>> +static ssize_t hvc_sbi_dbcn_tty_put(uint32_t vtermno, const u8 *buf, size_t count)
>>  {
>>         return sbi_debug_console_write(buf, count);
>>  }
>>
>> -static int hvc_sbi_dbcn_tty_get(uint32_t vtermno, char *buf, int count)
>> +static ssize_t hvc_sbi_dbcn_tty_get(uint32_t vtermno, u8 *buf, size_t count)
>>  {
>>         return sbi_debug_console_read(buf, count);
>>  }
>> --
>> 2.43.0
>>
>>
>
> Reviewed-by: Anup Patel <anup@brainfault.org>
>
> Thanks,
> Anup