From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A374424D73; Fri, 24 Jul 2026 12:19:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784895570; cv=none; b=p7CLmGp2yL+V3kvVesf/6QxhWmeEACPciALj3rFNSJXFxdIo7ZHY8JLIhvWjA1w1pomTqAuPsPj5SmBJ3iZ9Yn5CyZjJ13XeOY+kdkRpeA2ROjoKEpwdva7OtXkhMpY48aSpzRTNy17f2BIl3zg7Ul5K6k6F4ykuhpEobsb6jlU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784895570; c=relaxed/simple; bh=6uomoyV0iRv18desCe0Ak+BFbkxhWlYI9AcLsTwWEyo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ddUjE+sb2grijxLCPM9q5kVKvOgtOiRjwwb4K710jxFvAgWQmR+r3G3UPy3cTDa4N4E056C974Itr9ivGTdzjcmg6xnZbnSlM7oTcP5K63c9pm0MdbTHP+eCb0QQz9PpyUu8ajEnF3avEPunLgy3FcSSJe5nGWvJny96uNJPG4Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HGR1+R3U; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HGR1+R3U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 117CA1F00A3D; Fri, 24 Jul 2026 12:19:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784895568; bh=2NihTIkzvJJhL1oMJLkkInbq38KcecjKA4gcRVTiYro=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=HGR1+R3Utvf9qRUvr8MB/WEz/YIO7CFExPVMRcFsOjvGb/mhOz57ZZLW4G8DGzlKi jCwQSCoOos3aLTbrn+yAOjadJhCjxqFtgp9HIKSA/8w8HFoaR3wGdHKLDfDyBU6+2q UEm5YkrYt3eGQW/gl1td6o6mUmd9SCBwoHsaYarHVkiVTZJ3WLSkZsB9Z3yadfRBbl 7qSDulW2JajROCYIXjXaYTr6pL6MsHku94UmabQD/1FUWADB4qdHY1Wre6CSZgvu9G Frr1z5nG+wsonT8jDV84KcUak3r2w5opxI9vxJBJ0TNwlVkO7Uxl26TSeVloHdvLcN VghuxtNsSqVxg== Date: Fri, 24 Jul 2026 13:19:22 +0100 From: Sudeep Holla To: Andre Przywara Cc: Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" , Len Brown , James Morse , Ben Horgan , Reinette Chatre , Fenghua Yu , Jonathan Cameron , Srivathsa L Rao , Ganapatrao Kulkarni , Trilok Soni , Srinivas Ramana , Niyas Sait , Lee Trager , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 05/10] arm_mpam: propagate MSC access errors for __ris_msmon_read() Message-ID: <20260724-daffy-red-gazelle-3f70be@sudeepholla> References: <20260723155454.1760823-1-andre.przywara@arm.com> <20260723155454.1760823-6-andre.przywara@arm.com> <20260724-horned-wolf-of-will-a49c1d@sudeepholla> <1864c9a2-2e97-411e-9f12-862a8cfd4101@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1864c9a2-2e97-411e-9f12-862a8cfd4101@arm.com> On Fri, Jul 24, 2026 at 01:17:06PM +0200, Andre Przywara wrote: > Hi, > > On 7/24/26 12:02, Sudeep Holla wrote: > > On Thu, Jul 23, 2026 at 05:54:49PM +0200, Andre Przywara wrote: > > > Allow the function for RIS accesses to return an error, and propagate > > > read and write errors from the lower level up. > > > This function is a bit special, since it can be called via an SMP > > > helper, so the prototype must stay as void. So propagate any errors > > > using the "err" field in the struct passed in as the sole argument to > > > that function. > > > > > > > Not sure if this was already discussed by build bisection regresses between > > 4/10 and 5/10 as you change function prototype there and caller here or > > am I missing to read it correctly ? > > Does it? I build tested every patch multiple times yesterday, and just > repeated it, and it comes back cleanly. > > > > Signed-off-by: Andre Przywara > > > --- > > > drivers/resctrl/mpam_devices.c | 36 +++++++++++++++++++++++++--------- > > > 1 file changed, 27 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > > > index 9ee4eb4db03f..bcff53477133 100644 > > > --- a/drivers/resctrl/mpam_devices.c > > > +++ b/drivers/resctrl/mpam_devices.c > > > @@ -1328,6 +1328,10 @@ static u64 mpam_msmon_overflow_val(enum mpam_device_features type, > > > return overflow_val; > > > } > > > +/* > > > + * This function might be called via smp_call_function_any(), so propagate > > > + * errors inside the arg struct. > > > + */ > > > static void __ris_msmon_read(void *arg) > > > { > > > u64 now; > > > @@ -1351,7 +1355,9 @@ static void __ris_msmon_read(void *arg) > > > mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, ctx->mon) | > > > FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); > > > - mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); > > > + m->err = mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); > > > + if (m->err) > > > + return; > > > switch (m->type) { > > > case mpam_feat_msmon_mbwu_31counter: > > > @@ -1371,7 +1377,9 @@ static void __ris_msmon_read(void *arg) > > > * Read the existing configuration to avoid re-writing the same values. > > > * This saves waiting for 'nrdy' on subsequent reads. > > > */ > > > - read_msmon_ctl_flt_vals(m, &cur_ctl, &cur_flt); > > > + m->err = read_msmon_ctl_flt_vals(m, &cur_ctl, &cur_flt); > > > + if (m->err) > > > + return; > > > > > > > Atleast read_msmon_ctl_flt_vals() changed to return value in last patch. > > Ah, but this is not a problem that breaks the build, as we formerly just > ignored the (at this point bogus) error value, but now pass it up. Rather than return I was thinking about added parameter to get the read value. > But this is one occasion of "touching the same line twice", that was > criticised before. Not nice, but the alternative would be to have one giant > patch, which I figured to be unreadable. > Ah then good. May be I was overthinking. -- Regards, Sudeep